Doctor Who

Season 9

The Magician's Apprentice

1. Peter Capaldi was really playing the guitar during the Doctor's big entrance and for Pretty Woman.
2. Michelle Gomez confirmed on Twitter that her tickling a nearby Dalek's bumps when referring to the TARDIS as "the dog's unmentionables" was improvised.
3. Peter Capaldi had a say in picking the guitar and described it as "...like a Fender Stratocaster that had been described to someone who had never seen one...That (joke) is hilarious, if you're into guitars..."
4. To provide the necessary Dalek props, some were taken from the nearby Doctor Who Experience exhibition.
5. The planet Karn has appeared before in the new and original series. The Fourth Doctor visited Karn in "The Brain of Morbius" and the Eighth Doctor visited Karn during Doctor Who: The Night of the Doctor (2013).
6. An Ood, a Sycorax, the Hath, a Tivolian, the Shadow Proclamation, a Judoon and Ohila the high priestess of the Sisterhood of Karn all make cameos.
7. The design of the Dalek city and the sliding doors in it pays homage to the set of the first Dalek story, "The Daleks".
8. The Doctor's entrance references Peter Capaldi's time as the lead singer of a punk rock band in college.
9. This was the fifth story to be filmed in Spanish territory, with some filming done in Spain.
10. The title sequence was slightly modified starting with this episode; the clock gears, gas and the first Roman numeral clock face tunnel now have a purple hue.
11. It was unknown whether or not Jenna Coleman would be returning as Clara Oswald for Series 9. Rumours suggested she may be leaving in the Christmas Special (Doctor Who: Last Christmas (2014)). In the final scene of the Christmas Special, however, it was confirmed Coleman would be staying for part Series 9. It was officially announced Ms. Coleman will depart during this series, but, when, or how, is (as is normally the case), unknown.
12. The title of the episode was revealed just before the credits of the preceding Christmas Special. The title read: "The Doctor and Clara will return in The Magician's Apprentice".
13. First appearance of Clare Higgins as Ohila in a TV episode. She previously appeared in two webcasts, Doctor Who: The Night of the Doctor (2013) and Doctor Who: Prologue (2015).
14. The Doctor introduces Missy to the crowd as, "the Wicked Stepmother". In fairy stories, the stepmother is usually associated with jealousy or cruelty. However she also leads the protagonist into places that show off his or her best qualities.
15. When Clara and The Doctor finally meet up he mentions that he "Spent all of yesterday in a bow-tie. The day before in a long scarf." In saying that, he is probably referencing two of his previous incarnations - most likely the 11th Doctor and the 4th Doctor respectively.
16. When the Doctor and Davros are talking in Davros's ship, the Dalek creator's nose can be observed uncomfortably squished at an unnatural angle against his metallic hand owing to the latex texture of his face mask.
17. To keep Davros' return a surprise, Julian Bleach was not credited prior to airing. The young Davros, played by Joey Price, is not credited as Davros, but rather as "Boy".
18. First meeting of Davros and the Twelfth Doctor.
19. The episode contained Daleks from many previous appearances of Daleks throughout the run of both the old and new series.
20. The line "do not go gentle into that good night" that Clara says is the first line and title of a poem by Dylan Thomas. It is about death and survival.
21. A popular fan theory was seemingly made canon in this episode. Clara is bisexual. Oswin (a different version of Clara) jokingly referred to a girlfriend called Nina in a previous episode.
22. The episode contained Daleks from many previous appearances of Daleks throughout the run of both the old and new series. It was also largely filmed in the style of the Tom Baker era.
23. When Colony Sarff adopts his serpent form and speaks to the Doctor, his snake tongue darts out only with every "S"-sound he pronounces.

The Witch's Familiar

1. This episode saw a rare use of the mild expletive "bitch" on the series, spoken by Missy. This is notable as the episode premiered pre-watershed hours on BBC One and Doctor Who is often considered a family-friendly television series. To further denote the rarity of this language on the show, the expletive was last heard in Doctor Who: The End of the World (2005) by Rose Tyler, over ten years prior.
2. Davros says the Doctor is privileged to be able to use the only other chair on Skaro. This references Doctor Who: The Survivors (1963) (the second episode of "The Daleks", the first Dalek adventure), when Barbara comments that on the Daleks' world, "there wasn't any furniture, now I come to think about it..." It was also brought up in Comic Relief: Doctor Who - The Curse of Fatal Death (1999), where the Doctor and his companion were tied to chairs by Daleks; when his companion asked why the Daleks had chairs, the Doctor promised to "explain later".
3. This episode is not the first time the Daleks are shown to have a concept of mercy. Previously in Doctor Who: The Big Bang (2010), a Dalek says its records indicate that River Song will show mercy because she is a companion of the Doctor (and is subsequently proven wrong).
4. Missy is seen in a sewer. Previously, in the spoof Comic Relief: Doctor Who - The Curse of Fatal Death (1999) also written by Steven Moffat, an incompetent version of the Master was shown falling into an absurdly vast sewer three times and taking three hundred and twelve years to climb out each time.
5. Missy says that murdering Daleks is like golf to Time Lords. Ironically, this line was previously used in a different show Steven Moffat writes for - Sherlock (2010) - where the detective mentions that the activities of secret terrorist organizations are basically golf.
6. At 36:19 you see a Cyan Blue Dalek. This is a tribute to the original Dr Who (1963).
7. Both River Song and now Missy are now shown to carry handcuffs around with them.
8. This is the second 2-part episode since Peter Capaldi became the Doctor, after the season 8 2-part finale Doctor Who: Dark Water (2014) and Doctor Who: Death in Heaven (2014).
9. This is the second time that Clara has become a Dalek - the first was in Doctor Who: Asylum of the Daleks (2012).
10. When Clara hides inside the Dalek it is very similar to when one of the Doctor's original companions, Ian, hides inside a Dalek in the very first Dalek serial.
11. Missy almost carries through with her threat from Doctor Who: The Magician's Apprentice (2015) to scratch Davros's eye out, and ends up poking his mechanical eye.
12. Previously, in Doctor Who: Asylum of the Daleks (2012) the Doctor jokingly taunts the daleks by asking them to look up info on him from their database and says, "Come on, who's your daddy?" Ironically, it is now established that the Doctor does have some claim to being the dalek's daddy (or perhaps granddad).
13. A dying Davros telling the Doctor that he wants to look at him with his own eyes is very similar to a scene in Star Wars: Episode VI - Return of the Jedi (1983), when Anakin Skywalker/Darth Vader says he wants to look at his son Luke with his own eyes as he is dying. Like Davros, he too has been hooked up to mechanical apparatuses after suffering crippling injuries, including a mask over his face.

Under the Lake

1. When the Doctor is trying to say, "Go ahead," to Cass in sign language what he is actually saying is, "You're beautiful," which accounts for her surprise.
2. One of the cue cards Clara prepared for The Doctor reads: "It was my fault, I should have known you didn't live in Aberdeen." The Fourth Doctor had dropped an earlier companion, Sarah Jane Smith, off in a hurry in Doctor Who: The Hand of Fear: Part Four (1976). Toby Whithouse (the writer of this episode) had revealed in an earlier episode, Doctor Who: School Reunion (2006), that she had been left in Aberdeen when she actually lived in Croydon.
3. One of the cue cards from Clara reads: "No-one is going to get eaten / vapourised / exterminated / upgraded / possessed / mortally wounded /] turned to jelly we'll all get out of this unharmed"
4. Cass is the Second character to be played by a deaf actor in the history of the series. The First being Tim Barlow who played Tyssan in Destiny of the Daleks.
5. One cue card reads: "I didn't mean to imply that I don't care".
6. Another cue card says: "I completely understand why it was difficult not to get captured".
7. Three Star Trek characters are painted into the scene on the wall in the mess.
8. At the start when The Doctor's about to pick up his guitar, the brand of the amplifier in the background is 'Magpie Electrics.' This same brand is used in a previous episode, 'The Idiot's Lantern.' It was the name of the T.V. company
9. The Doctor says in passing he had met Dame Shirley Bassey (and, apparently this got him very excited).
10. The "Readthrough Draft" of the script for this episode was titled "Ghost in the Machine".
11. The cue card The Doctor read out was "I'm very sorry for your loss. I'll do all I can to solve the death of your friend / family member / pet" but the "/" was read out as "slash".
12. This episode takes place from November 21 to November 24, 2119.
13. Actor Steven Robertson was a regular on Toby Whithouse's Being Human (2008) (TV Series).
14. Vector Petroleum sounds like Victor Pemberton who wrote the serial "Fury from the Deep", another water-themed base-under-siege story.
15. The scene where Clara is leading the ghosts into a trap. She runs in a corridor and the door shuts behind. The serial number on the door reads 1701B, the registration number of the USS Enterprise B from Star Trek: Generations (1994).

Before the Flood

1. The Doctor's guitar amplifier is branded Magpie Electronics - a nod Doctor Who: The Idiot's Lantern (2006) when The Tenth Doctor and Rose go back to the Queen's coronation. The maker of the possessed TV sets was Magpie Electronics.
2. The opening credits have an electric guitar backing track of the Doctor Who (2005) theme, played by Peter Capaldi.
3. Sophie Stone, who plays Cass, was the first deaf person to be accepted to RADA, the Royal Academy of Dramatic Arts.
4. This is the first episode of new Doctor Who where the Doctor talks to the audience and has only happened twice before with the fourth Doctor (1974-1981) and William Hartnell (1963-1966)
5. The actor playing the Fisher King is the UK's tallest man, Neil Fingleton.
6. The funeral director's calling cards are in the shape of a gravestone, and read, 'Albar Prentis, Universal Funeral Director - May the remorse be with you'
7. The "Bootstraps" phenomenon was also demonstrated in the Season 8's "Listen." The Doctor tells a young Rupert (Danny) Pink that fear is a superpower, which Clara hears, and later she tells a young Gallifreyan boy (later to be The Doctor) who is frightened of the dark that same speech the Doctor gave to Rupert.
8. When the safety protocol is active, a hologram of the Doctor appears wearing the last season costume. That means that he recorded this message sometime before the events of the series 9.
9. When the Doctor is talking about Beethoven and calls the event a "Bootstrap Paradox" it is a reference to the 1941 Robert Heinlein story "By His Bootstraps" about a man named Bob who meets an elderly man with a time machine that sends him on a time travel adventure, encountering several versions of himself at the same point in time, and later discovers he was the elderly man in the first place, and only sent himself on the adventure to ensure he turned out the way he did because of the adventure.
10. The Doctor's album of Beethoven's 5th is a recording of the Pittsburgh Symphony Orchestra conducted by William Steinberg and released in 1967.
11. When the Doctor is talking to Clara about changing the future he compares the changes to "ripples in a pond". The Seventh Doctor used practically the same comparison in the classic series in the serial "Rememberance of the Daleks".
12. This episode takes place in 1980 and on November 24, 2119.
13. At the start of the episode, The Doctor Breaks the fourth wall and talks to the audience and discusses the 'bootstrap paradox'. The Fifth and Tenth Doctors experienced a bootstraps paradox in the mini-episode 'Time Crash'. In this instance, both Doctor's Tardis' occupied the same space, potentially causing a major event. The Tenth Doctor managed to avert the disaster. When the Fifth Doctor asks the Tenth Doctor how he knew what to do, the Tenth Doctor explains he knew what to do because, when he was the Fifth Doctor, he watched and remembered what he had done as the Tenth Doctor.
14. The real Beethoven had a hearing impairment, like Cass does.
15. Peter Serafinowicz, who provided the voice of The Fisher King, starred opposite Karen Gillan in Guardians of the Galaxy (2014).
16. Although he didn't dangle her 'out the window', the Eleventh Doctor did previously dangle Amy Pond out the door on her first TARDIS flight so that she could experience weightlessness in Doctor Who: The Beast Below (2010).
17. While Peter Serafinowicz is voicing the main monster, the Fisher King, Slipknot's Corey Taylor was brought in to supply its scream. Producer Derek Ritchie has said that Taylor "has one of the most well-known screams in the history of music. We now have the most incredible roar for our incredible monster! He now sounds as terrifying as he looks!"
18. When the Doctor first meets Prentis, listen closely for a distant crash. O'Donnell turns her head slightly in reaction. The sound is, of course, the future Bennett trying to warn O'Donnell and being restrained by the future Doctor.
19. Clara tells the Doctor he can die with whoever comes after her. In fact, the Twelfth Doctor does die in the following season with his next companion, Bill.

The Girl Who Died

1. The name Ashildr (or Áshildur in present day Icelandic) is a composite of the words "Ás", the singular form of Æsir (Norse mythology gods), and "Hildur", a word-turned-name which most commonly means female warrior, Valkyrie or warfare in broader terms. In essence, her name thus means War Lord, a name which has strong ties with the Classic series.
2. When working on the alien helmet, the Doctor says he is 'reversing the polarity of the neutron flow' - this was a favourite saying of the Third Doctor.
3. Guest star Maisie Williams is best know for playing Arya Stark on Game of Thrones. Her on-screen brother in that series was played by Richard Madden, who was the real-life boyfriend of Jenna Coleman.
4. The alien "Odin" wears a helmet with one eye covered. This is similar to the actual myths about Odin, who plucked out one of his own eyes in exchange for a drink from the Well of Knowledge.
5. Brian Blessed was cast as Odin, but pulled out because of serious illness so David Schofield took over the role.
6. An enemy called The Mire also appeared in The Chase (1965). Although, the Mire in this episode is different from the one in the previous episode.
7. In a deleted scene on the DVD release, Clara compares the sword training of the Viking villagers with the long-running comedy Dad's Army (1968) which was about a rag-tag group of British Home Guard volunteers who were too old or otherwise unfit for military service.
8. The front cover of the book the Doctor flips through during Ashildr's monologue looks remarkably similar to the back cover of the Lindau Gospels with its cross pattee design. The actual back cover of the Lindau Gospels is the most intact example of very early Insular (British Isles contemporary with the Vikings) metal book-covers, and probably was originally a front cover from a book such as the Lindisfarne Gospels or Book of Kells (whose original covers have not survived).
9. Sean Pertwee was offered Odin.
10. Electric eels are found in the viking village, although they only appear naturally in South America.
11. Ashildr says that the girls in the village called her a boy. In Game of Thrones Maisie Williams character cut her hair to disguise herself as a boy.
12. Explains the link between the Twelfth Doctor's face being the same as Caecillius in Fires Of Pompeii.
13. The appearance of the Mire "Odin" (bearded 'god' in the sky amongst clouds) is quite similar to the appearance of God to King Arthur and his knights in the 1975 comedy film "Monty Python and the Holy Grail".

The Woman Who Lived

1. This is the 100th story of the revived Doctor Who (2005) series.
2. The Doctor blames the Terileptil for starting the Great Fire of London, when it was actually the Fifth Doctor who accidentally started the fire, although it was a Terileptil weapon that caused it to get out of control (again accidentally). He also teamed-up with a highwayman in that story too.
3. Among the handbills visible by the gallows is one advertising "A Tryal of Witches." This bill is in fact a replica of the actual cover of the pamphlet of that name describing the trial held before Sir Matthew Hale of two witches. The trial took place on 10 March 1662 (misprinted in the pamphlet as 1664) at Bury St. Edmunds in Suffolk, and this pamphlet was printed in 1682. The two witches were named Rose and Amy (the names of two of the Doctor's former companions).
4. The Doctor informs Me that she may come across Captain Jack Harkness in the future, given that his life, like hers, is indefinitely extended. The Doctor already expressed his dislike and avoidance of immortals in a conversation with Jack in Doctor Who: Utopia (2007).
5. The Medieval book with the jeweled cover from Ashildr's village is in her study on a lectern next to the fireplace.
6. This marks the first full length Twelfth Doctor story to feature Clara Oswald in a lesser role, only appearing at the end.
7. Ashildr mentions that she fought at the Battle of Agincourt. The episode was first broadcast the day before St Crispin's Day October 25, 2015, the 600th anniversary of the battle.
8. Ashildr mentions that she was at Agincourt and this episode was broadcast the day before the battle's 600th anniversary. Also, the Fourth Doctor once told Leela that she would have enjoyed Agincourt, implying that he was also there.
9. Struan Rodger previously voiced the Face of Boe. He also appeared with Maisie Williams as Three-Eyed Raven in Game of Thrones (2011).
10. The Doctor states that he is "on record as being against banter". This is a reference to Doctor Who: Robot of Sherwood (2014) when the Doctor chastises Robin Hood and his Merry Men for their lighthearted banter.
11. With his Scottish accent, it is no surprise that the Doctor failed to convince the English pikemen that he had a Dunbar medal from Cromwell. The real Dunbar medals were awarded by Cromwell to his troops for the victory of the English Parliamentarian forces over a Scottish Royalist army in the Battle of Dunbar on 3 September, 1650.
12. Ashildr sarcastically asks the Doctor how many Claras he had lost, yet he had actually lost several since Clara was fractured into his time-stream and died saving him at least twice.
13. This episode was filmed at the same time as Doctor Who: The Girl Who Died (2015).
14. This episode takes place in 1651.
15. Ashildr speaks of reading her diaries and drinking pomace wine. When you press grapes for their juice there is a mass of skins, seeds and a little pulp left behind; this is pomace. If you add water to that and ferment it you get a weakly flavored wine with very low alcohol content. In ancient times this was slave's wine.
16. According to an interview with writer Catherine Tregenna in DWM 492, the story is set in Hounslow.
17. The necklace Clara is wearing at the end of the episode is clearly a reference to Doctor Who: Face the Raven (2015) .
18. Rufus Hound previously appeared on Doctor Who Live: The Next Doctor (2013), the live show that announced that Peter Capaldi was going to be the next Doctor. He was then on The Science of Doctor Who (2013).
19. Snapping a bowstring without an arrow on it (as the Doctor does with Ashildr's Agincourt bow) is known as "dry firing" and is very damaging to wooden bows, since without an arrow to propel forward all the energy from the draw goes into forcing the bow-limbs back much more quickly than normal.
20. Maisie Williams' character Ashildr echoes the figure of "Wowbagger The Infinitely Prolonged" from Douglas Adams' novel "Life, the Universe and everything". Adams famously used to write Doctor-Who-scripts for before he became a world-famous novelist. "Most of those who are born immortal instinctively know how to cope with it, but Wowbagger was not one of them. (...) He had his immortality inadvertently thrust upon him by an unfortunate accident (...)" When his ennui finally becomes unbearable, Wowbagger tries to distract himself by insulting the Universe. "That is, he would insult everybody in it. Individually, personally, one by one, and (this was the thing he really decided to grit his teeth over) in Alphabetical Order."
21. Ashildr lives a double life as the highwayman Lord Knightmare and as the aristocrat Lady Me. In the 2009 special Doctor Who: Planet of the Dead (2009) (TV Episode) The 10th Doctor's on-off companion in that story was Lady Christina De Souza (Michelle Ryan) an aristocrat and jewel thief.
22. Karen Seacombe played Sandra in Doctor Who: The Lodger (2010).
23. Ashildr's masquerading as the highwayman "Lord Knightmare" is a nod to the popular British fantasy adventure game show Knightmare (1987).

The Zygon Invasion

1. There is a portrait of William Hartnell (the first Doctor) on the wall at the U.N.I.T. safe house.
2. Osgood continues to be a living homage to previous incarnations of the Doctor by wearing a shirt with question marks on the collar, also worn by the 4th and the 5th Doctor.
3. There is a real town in New Mexico called "Truth or Consequences." The town's name was changed from "Hot Springs" on 31 March 1950 after Ralph Edwards, the host of the popular game show "Truth or Consequences," called for any town in America to do so - in celebration of the show's ten year anniversary.
4. Kate Stewart being unsure over which decade the Zygons first attempted to invade in, the '70s or the '80s, is in reference to the ambiguity over whether or not the original UNIT stories took place in the present or the near-future of their mid-70's air dates. The invasion that she specifically mentions was shown in the Tom Baker serial Doctor Who: Terror of the Zygons: Part One (1975).
5. The naval surgeon at Porton Down is Harry Sullivan, a one-season companion of the Fourth Doctor. The Brigadier told the Fifth Doctor that Harry had been seconded to Porton Down on a hush-hush project in Doctor Who: Mawdryn Undead: Part Two (1983).
6. The Doctor remarks that he once "snogged a Zygon". The Tenth Doctor kissed a Zygon impersonating Queen Elizabeth in Doctor Who: The Day of the Doctor (2013).
7. The only time that Osgood appears without an obvious clothing item relating to the Doctor is when she is in her mourning outfit.
8. Following from her appearances in Doctor Who: The Day of the Doctor (2013) and Doctor Who Extra: Death in Heaven (2014), both Osgoods are shown wearing costume elements of the Doctor's earlier incarnations. In addition to the Fourth Doctor's scarf, one Osgood is shown with a bow tie similar to the Eleventh Doctor's, while the other wears a question mark-decorated tank top similar to that worn by the Seventh Doctor. Both have shirts with question marks on the collar points, a common element of the Fourth, Fifth and Sixth Doctors' outfits. Osgood asks the Doctor why he does not use the question mark motif anymore, to which he replies that he still does - on his underpants.
9. When the Doctor boards the UNIT presidential command plane, he turns and flashes a "V-for-victory" with both hands, in exactly the same pose that Richard Nixon did just as he boarded Marine One on the day he resigned. The 11th Doctor had met President Nixon previously.
10. "New Mexico" scenes were filmed in Italy. There are some bits of Fuerteventura in "New Mexico" as well.
11. The entry for the Doctor in Osgood's mobile is for a "T.A.R.D.I.S. Direct Link", and for an icon picture has a red question mark in the same style as the ones on her (and the former Doctors') lapels.
12. The Doctor says he never stopped wearing question marks, as he wears question mark underpants. His eighth incarnation wore question-mark boxer shorts, suggesting his war, ninth, tenth, and eleventh incarnations also did.
13. The conversation that the Doctor and Kate Stewart have over the Zygons being a "splinter group" -- and how bombing them would only radicalize the others who would otherwise wish to live peacefully -- appears to be an overt commentary on the ISIS international terrorism crisis and the violent response from many world leaders and politicians against not only the terrorists, but also the Muslim populations they claim to represent.
14. The Radio Times programme listing was accompanied by a small colour shot of Osgood and the Doctor, with the accompanying caption "Doctor Who / 8.15 p.m. Osgood is snatched by aliens, prompting a round-the-world rescue mission".
15. The Osgood video where they show the Osgood Box is filmed in B/W, and it is not possible to determine the colour of the box from the video. But when the scene is shown from the camcorder operator's POV, with closeups on both Osgoods, the box appears to be orange.
16. The shot near the end of Clara's clone troops marching down a tunnel seems to be a very nice reference to a similar scene during Run Like Hell in Pink Floyd: The Wall (1982). Both feature goose stepping troops, dressed in black, in formation, in a tunnel, back lit, and very low camera angles.
17. The director, Daniel Nettheim, is the nephew of actor David Nettheim who had a small role in "Doctor Who: The Enemy of The World", a Patrick Troughton-era serial.
18. Peter Capaldi and Rebecca Front worked together on The Thick of It (2005), a comedy series.
19. When The Doctor is introducing himself as President of the World he gets a 'Yes, we know who you are' in response. This is a callback to the reply often received by Prime Minister/Former Prime Minister Harriet Jones in the Tenth Doctor's era.
20. A brief shot shows a UNIT UAV being loaded with chemical canisters. This appears to be a replica of a U.S. Shadow 200, built by AAI Corporation in Maryland.
21. The climax of this episode features Bonnie, while impersonating Clara, holding a shoulder mounted missile launcher and opening fire on the plane the Doctor is onboard. By coincidence, the episode was broadcast only a few hours after 2015 Sinai Peninsula massacre, where terrorists from the Islamic State of Iraq, the Levant and Syria placed a bomb on Metrojet Flight 9268, killing all 217 passengers and seven crew onboard.
22. The name of the town featured in this episode, Truth or Consequences, is also the name of an episode of Lie to Me (2009), which also starred Gretchen Egolf.
23. The Doctor playing a fairly wild version of "Auld Lang Syne" on his electric guitar is a nod to Jimi Hendrix, who once said, " It's not about being better, you know, or anything-anything like that. You know, it's about being inspired. And I'm inspired by everybody. I'm inspired by all kinds of people. You know, it's art to me. You know, and with art- it's just showing something that you've never seen before. Or-Or even if it's something that you see every day just showing it in a new way, you know. So I should-I should be able to take, like, any song and- I should be able to take Auld Lang Syne and do it in a new way you've never even heard it before. You know what I mean? So- it's all inspiration and inspiring other people." Jimi himself played Auld Lang Syne at the Fillmore East once.
24. Return of Osgood, who was presumably killed in "Death in Heaven".

The Zygon Inversion

1. Kate describes how she escaped from a Zygon by saying "Five rounds, rapid." This phrase was first used by her (Doctor Who-universe) father, The Brigadier, in Doctor Who: The Dæmons: Episode Five (1971) and the name of the actor's memoir: "Five Rounds Rapid! The Autobiography of Nicholas Courtney - Doctor Who's Brigadier."
2. The helmet which Ashildr used to defeat the Mire is stored in the Black Archive.
3. Osgood has now worn the 12th Doctor's sonic sunglasses, continuing her tradition of wearing items from the various Doctors.
4. The Doctor claims that he himself planned to use a box with a button to commit mass murder. This is a reference to Doctor Who: The Day of the Doctor (2013) when three of the Doctor's past incarnations planned to use the Moment, a Time Lord doomsday device, to end the Time War.
5. According to Peter Harness, the Doctor's de-escalation speech originally included several additional sections. These were cut out of the final draft of the script, mostly for pacing reasons. One of the sections included the Doctor asking Bonnie about whether everyone will be forced to grow and eat beetroot. During a convention appearance in New Zealand a few weeks after the episode aired, Peter Capaldi performed a version of the complete speech.
6. Osgood says that there has been more than one meaning for the acronym TARDIS. The 'D' in TARDIS has been given as both "dimension" and "dimensions" during both the classic series and the revival, giving the name TARDIS two different meanings. In Doctor Who: The Next Doctor (2008), Jackson Lake says his 'TARDIS' - in reality, a hot air balloon-stands for "Tethered Aerial Release Developed In Style". In this episode, the Doctor gives it yet another meaning: "Totally And Radically Driving In Space".
7. As he departs, the Doctor tells the Osgoods that "I'm a very big fan", the same thing Osgood says to the Eleventh Doctor in Doctor Who: The Day of the Doctor (2013).
8. The safe from which Bonnie recovers the laptop is hidden behind a portrait of The First Doctor played by William Hartnell.
9. The Fourth Doctor's companion Harry Sullivan is mentioned in this episode by name (he was only alluded to in the prior episode) as developing Z67 - "Sullivan's Gas" - as a means of stopping the Zygons. The Doctor also refers to Sullivan as "the imbecile", a reference to Doctor Who: Revenge of the Cybermen: Part Four (1975), where the Doctor shouted "Harry Sullivan is an imbecile!" after Sullivan triggered a rockslide and then tried to remove a Cyberbomb from the Doctor without deactivating the booby trap.
10. UNIT's Black Archive, first seen in Doctor Who: The Day of the Doctor (2013) and containing items from several past episodes, currently has a Mire battle helmet first seen in Doctor Who: The Girl Who Died (2015).
11. This episode begins with an 'awake' Clara beginning her day, only she's actually imprisoned inside of a Zygon pod. This is very similar to the first time the Doctor met Clara (Oswin); she was encased within a Dalek body, but, her mind believed she was in a crashed spaceship, baking soufflés.
12. Another example of one of the Osgoods wearing Doctor-inspired clothes, is when the 3rd Osgood (who previously had been Bonnie, and Zygella) wears the duffel coat and Paisley scarf which the Seventh Doctor wore in Doctor Who: The Curse of Fenric: Part One (1989). It was notable, because it was designed to hide the reveal of his outfit, but, because the BBC changed the serials' airing order, it was instead shown in the previous story; "Battlefield".
13. Whilst walking with Osgood, the Doctor reveals his first name to Osgood - under the proviso she does, likewise. He says his first name's 'Basil,' and Osgood says her first name's 'Petronella.'
14. Bonnie glances in a mirror at the UNIT safe house, and for a brief moment, sees Clara instead of her own reflection. Also visible in the mirror, is a photograph of the two Osgoods, which sits on a desk.

Sleep No More

1. Due to the episode's uniqueness and originality, plot and production details were kept very secret. Despite releasing paragraph length plot summaries for each episode in advance of its airing, all the BBC released for this episode was: "This is footage collected from a space rescue mission. If you value your life, your sanity, and the future of your species, DO NOT WATCH IT".
2. Mark Gatiss has spoken about the episode saying "Well, I've had this story in my mind for a long time. It's set in the future. It's all from different points of view, which has not been done before on Doctor Who (2005). It's been quite a challenge to make because you have to break a lot of the usual rules in terms of what you can actually show. Anything you can do to shake the format up is very exciting and that's what we've done."
3. In order to get the character point of view, the camera operator dressed up as character, held props, and would recite lines of the character he was portraying.
4. The Great Catastrophe is the near-collision with the Sun that was first mentioned in Doctor Who: Frontios: Part One (1984). In both episodes, the Doctor mentions the catastrophe and then tells his companion that they have all that to look forward to.
5. This is the first episode to have no opening titles.
6. This was supposed to be a two-parter, like most of the others in series 9, but Mark Gatiss felt it couldn't be sustained over two installments and making it a one-off gave it a sense of immediacy.
7. The space station is named after Urbain Le Verrier, the French mathematician who predicted the presence of Neptune (the planet the space station orbits) from oddities in the orbit of Uranus.
8. Steven Moffat commissioned a follow-up story from Mark Gatiss before this one even aired, but it was ultimately replaced by Doctor Who: Empress of Mars (2017) when Series 10 was actually produced.
9. Producer Nikki Wilson also played the voice of the annoying computer that wouldn't allow Deep-Ando through a door unless he sang the Sandman song.
10. At one point in the episode, The Doctor says, "When I say run, run!", a commonly used phrase of the second Doctor as played by Patrick Troughton. Reece Shearsmith, who plays Rassmussen in the episode, played Troughton in An Adventure in Space and Time (2013). It is also the famous final words of Sherlock Holmes to Irene Adler, the one adversary he never beat, in the series Sherlock (2010) Season 2 Episode 1, Sherlock: A Scandal in Belgravia (2012), which is also written by Mark Gatiss and produced by Steven Moffat
11. This is the first episode to have its title in the end credits, although the "Doctor Who" logo can be seen vertically in the text-burst near the start. This was Mark Gatiss's idea, inspired by The Blair Witch Project (1999).
12. This is the first episode to feature an openly transgender actor, Bethany Black.
13. The Doctor comments that letting Clara name the Sandmen was like the naming of the Silurians. However, while someone else deduced they came from the Silurian era, it was the Doctor who first called them "Silurians". After complaints from scientists that they couldn't come from that time, in Doctor Who: The Sea Devils: Episode Two (1972), the Doctor admitted it was a misnomer.
14. The Shakespeare quote the Doctor recites is from the play Macbeth, Act 2, Scene 2.
15. Reece Shearsmith has previously played Patrick Troughton/the Second Doctor in An Adventure in Space and Time (2013).
16. This is the only episode in series 9, that couldn't be considered a part of two-parter or three-parter.
17. Clara asks if the Morpheus Machine is actually named after Morpheus, the god of sleep. The Morpheus hologram also uses the term 'in the arms of Morpheus', a phrase meaning to be in a deep sleep.
18. This is the first Doctor Who (2005) episode written by Mark Gatiss that is set in the future.
19. Mark Gatiss had visited the countries Japan and India prior to writing this episode, which in turn inspired the use of them in this episode.
20. Whilst it is true this episode is the 'first of found footage,' the story itself, being told by flashback, isn't.Previously done with Doctor Who: Love & Monsters (2006).
21. This episode takes place in the 38th Century.
22. Reece Shearsmith is the last of the three main actors from The League of Gentlemen (1999) to appear in Doctor Who (2005). Mark Gatiss featured in Doctor Who: The Lazarus Experiment (2007) (and three subsequent episodes) and a year later Steve Pemberton was in the two-parter Doctor Who: Forest of the Dead (2008)/Doctor Who: Silence in the Library (2008).
23. "Mr. Sandman" was previously performed in "Delta and the Bannermen".
24. The Radio Times programme listing was accompanied by a small colour head-and-shoulders shot of a helmeted Nagata, with the accompanying caption "Doctor Who / 8.15 p.m. / Found footage shows what fate befell the rescue mission led by Nagata (Elaine Tan)".
25. As of 2018, this episode holds the title of the lowest rated episode of the revival covered on IMDb (6.1 stars out of 10) until it was surpassed by The Tsuranga Conundrum.
26. Six feet eight inch tall Paul Davis, who played the King Sandman, has previously worked with Reece Shearsmith in horror short Him Indoors (2012), which Davis wrote and directed.
27. The space station in this story is named after French mathematician Urbain Le Verrier.
28. "Sleep that knits up the ravelled sleeve of care..." is a slightly mangled passage from Shakespeare's Macbeth: Act 2, Scene 2.
29. In the scene where the rescue team meets the Doctor and Clara, Nagata starts to say "Right, you're to consider yourself..." and the Doctor finishes her sentence by playfully singing "part of the furniture!", this is a reference to the song "Consider yourself" from the musical "Oliver!" which has that line.
30. Reece Shearsmith is such a big fan of the series he is even a devoted fan of Doctor Who: Timelash: Part One (1985), which is widely regarded as one of worst stories of the original run.
31. Those like Chopra who refuse to compress their sleep via the Morpheus process are referred to as 'Rips'-a reference to the short story "Rip Van Winkle" by Washington Irving.
32. Sleep machines that compress a whole night's sleep into a few minutes is used in Judge Dredd stories to maximise the time the Judges spend enforcing The Law.

Face the Raven

1. The Retcon drug has often been used in Torchwood (2006).
2. There is a poster on the wall of the alley which shows the diagram of a flux capacitor (from the 'Back to the Future (1985)' films) and the writing on it says "Delorean" in Aurebesh (the main alphabet in the Star Wars (1977) franchise).
3. In Doctor Who: The Time of the Doctor (2013), Matt Smith's Eleventh Doctor asks 'Handles', his traveling companion at the time, to remind him to redirect the telephone through the main console unit. This is the first episode in which we see that that has been done.
4. After examining Rigsy the Doctor flips through his "nice" cue cards and one them reads: "I could be wrong, let's try it your way".
5. Robin Soans has a minor role as the Chronolock Guy. He is one of 38 actors to have also acted in the 20th Century Doctor Who (1963) - Soans was in the Tom Baker serial Doctor Who: The Keeper of Traken: Part One (1981) as Luvic, one of the five Consuls of Traken.
6. 'Simon Paisley Day' returns as Rump, having previously played the Steward in Doctor Who: The End of the World (2005) in the first season of the new Doctor Who (2005) series back in 2005.
7. Just before the raven strikes, the name "ROSKILLY'S" is seen on a storefront. As the raven strikes, the rest of the name is very briefly obscured leaving "KILL".
8. The cot has a young raven painted on just above the head of the baby.
9. A hidden, Old Worlde-looking street in London was a key location in Neil Gaiman's Neverwhere (1996), which also starred Peter Capaldi. Gaiman would later go on to write the Doctor Who (2005) episodes Doctor Who: The Doctor's Wife (2011) and Doctor Who: Nightmare in Silver (2013). Another similar street, Diagon Alley, appears in the "Harry Potter" stories, which were referenced several times in Doctor Who: The Shakespeare Code (2007).
10. Kabel (played by Simon Manyonda) is a Lugal-Irra-Kush, a species we first saw in Doctor Who: The Rings of Akhaten (2013).
11. This is the first story to feature the Twelfth Doctor in a burgundy version of his signature navy blue Crombie coat, similar to the coat he was first seen wearing during Doctor Who: The Day of the Doctor (2013).
12. In the credits, the word "Oods" is used to denote more than one Ood, rather than the established "Ood", as used in Doctor Who: The Impossible Planet (2006).
13. Joivan Wade originally appeared as Rigsy in Doctor Who: Flatline (2014).
14. 'Simon Paisley Day' appeared in The Musketeers (2014) with Peter Capaldi.
15. No fewer than six of the performers in Face the Raven have appeared in Marvel or DC projects. Jenna Coleman (Clara) portrayed Steve Roger's date at the beginning of Captain America: The first Avenger. Maisie Williams (Ashldr) was Rhane Sinclair/Wolvesbane in The New Mutants. Jovian Wade (Rigsy) is Victor Stone/Cyborg in The Doom Patrol. Simon Manyonda (Kabel) is Lucius Fox in Pennyworth. Letitia Wright (Anahsan) is Shuri in the Black Panther films. Peter Capaldi (The Doctor) is The Thinker in The Suicide Squad.
16. The Doctor tells a young boy to "remember 82". Adric who was a companion of the fifth doctor died in Doctor Who: Earthshock: Part Four (1982), broadcast in 1982.
17. This story takes place in a sanctuary for various misfits and aliens. One of the residents is a two faced character. This may be a nod to Sanctuary (2008) where strange people and creatures are protected. There is a two faced person there too.
18. Sometime between the filming of Doctor Who: The Woman Who Lived (2015) and this episode, Maisie Williams got a nose piercing, which meant that between the 17th century and the late 2010s, Ashildr got her nose pierced.
19. A scene cut from the episode had the Doctor carrying Clara's body indoors and orders Ashildr not to wipe Rigsy's memory, so that Rigsy can tell Clara's family and take care of her body.
20. Clara tells the Doctor: "You don't need to be a warrior. Promise me. Be a Doctor." In Doctor Who: The Night of the Doctor (2013) the Eighth Doctor (Paul McGann) says to Ohila: "I don't suppose there's a need for a doctor any more. Make me a warrior now." She then gives him the potion to change into the War Doctor (John Hurt). In the pivotal part of Doctor Who: The Day of the Doctor (2013) she describes the War Doctor and the Tenth Doctor (David Tennant) as the warrior and the hero and says: "We've got enough warriors. Any old idiot can be a hero." When the Eleventh Doctor (Matt Smith) asks about himself she, says: "What you've always done. Be a doctor." So the Twelfth Doctor (Peter Capaldi) is the fourth Doctor she's talked back from the brink with variations on the same reasoning.
21. Clara is the second recurring companion to die onscreen since the show's revival in 2005, and in fact the second since Adric in Doctor Who: Earthshock: Part Four (1982) (1982). Both stories included Cybermen, and in both stories the companion inadvertently became an indirect cause of their own death, while trying to save someone else.
22. This is the third time an incarnation of Clara has died onscreen. She first appeared as "Oswin Oswald" (aka "soufflé girl"), a human who had been turned into a Dalek, but gone mad and still thought she was human, in Doctor Who: Asylum of the Daleks (2012). Another incarnation, "Clara Oswin Oswald" later appeared in Victorian England in Doctor Who: The Snowmen (2012); after her death, the Doctor discovers the connection between the two. He then encounters the recurring companion Clara in present-day England, in Doctor Who: The Bells of Saint John (2013). The mystery of the connection between the incarnations was a running arc through the second half of series 7, finally resolved in Doctor Who: The Name of the Doctor (2013).
23. Ashildr/Me (Maisie Williams), who was originally introduced as a Viking, brings about the death of Clara using a raven. In Norse mythology, Odin's ravens were often associated with the dead.
24. Rigsy's portrait of Clara that adorns the TARDIS doors in the post-credit sequence is based upon a publicity photograph of Jenna Coleman used to promote her appearances at science fiction conventions.
25. This was originally written as a standalone story, with Rigsy, Ashildr, and the Story Arc plot developments (i.e. Clara's death) added later. In fact, it was originally announced as a standalone episode like Doctor Who: Sleep No More (2015), but shortly after Doctor Who: The Woman Who Lived (2015) aired it was confirmed that this episode would pay off its Sequel Hook, and by the time it aired it was clear that its events would have a huge impact on the Series 9 arc.
26. This marks the first episode to have a post-credits "Next Time" sneak preview. Previously, Doctor Who: Death in Heaven (2014) had a mid-credits scene, but this is the first to have a post-credits one.
27. In the sequence where Clara takes the tattoo from Rigsy, she was scripted to address him by his full name while persuading him.
28. In the episode {The Power of Three (2012) (7.4) }_ UNIT Director Kate Stewart answers Amy Pond's question in a possibly tongue in check way, when Amy asks about UNIT HQ. Amy Pond: "Secret base below the Tower? Hope we're not here because we know too much." Kate Stewart: "Yes, I've got officers trained in beheading. Also, ravens of death." This could be brilliant Steven Moffat's_ foreshadowing for this episode.

Heaven Sent

1. The full quote from "The Shepherd Boy" in the book "Household Tales" by the Brothers Grimm is:The King said, "The third question is, how many seconds of time are there in eternity." Then said the shepherd boy, "In Lower Pomerania is the Diamond Mountain, which is two miles and a half high, two miles and a half wide, and two miles and a half in depth; every hundred years a little bird comes and sharpens its beak on it, and when the whole mountain is worn away by this, then the first second of eternity will be over."
2. Writing in Doctor Who Magazine #495, Steven Moffat confirmed that the portrait of Clara was painted by the Doctor himself.
3. The skull the Doctor finds is based on Peter Capaldi's own bone structure - the effects team reverse-engineered the shape of his skull from a lifecast that was taken to create the "ghost Doctor" prosthetics for Doctor Who: Under the Lake (2015)/Doctor Who: Before the Flood (2015).
4. The Doctor says "Assume you're going to survive. Always assume that. Imagine you've already survived." This picks up the theme from the first story - in the Doctor Who: The Witch's Familiar (2015) Clara says the Doctor always wins, "Because he always assumes he's going to win. He always knows there's a way to survive. He just has to go and find it."
5. While imagining talking to Clara, the Doctor breaks the fourth wall, looks at the camera and says "I'm nothing without an audience".
6. When the Doctor first sees himself on the monitor in the castle, there is writing on the stone wall next to the window that is briefly visible in the shot. The lettering is black with red capitals, and it is the opening voice over of this episode ("As you come into this world...") with a few lines missing.
7. Each and every one of the skulls in the episode are modelled from Peter Capaldi's own skull.
8. The episode is a "one-hander" featuring only The Doctor (played by Peter Capaldi) and a monster called The Veil (with Jami Reid-Quarrell, who was Colony Sarff in the season's opening two-parter, doing the motion-capture work for it). Clara (Jenna Coleman) also appears inside the Doctor's "storm room".The only true official one-hander story up to this point was Doctor Who: Clara and the Tardis (2013).
9. In this Twelfth Doctor story the room that led out of his prison was number 12. In the Eleventh Doctor story Doctor Who: The God Complex (2011), his greatest fear was in room 11.
10. Jenna Coleman's name has been removed from the opening credits, making this the first regular episode of the revived series to only credit one actor during the title sequence. To make up for the extra time required, 'Peter Capaldi's name is held on screen for a couple of seconds before moving away, also a first.
11. The Doctor says he is "good at traps". In Doctor Who: The Time of Angels (2010), the Eleventh Doctor said "Didn't anyone ever tell you there's one thing you never put in a trap? If you're smart, if you value your continued existence, if you have any plans about seeing tomorrow, there is one thing you never, ever put in a trap... Me."
12. The motif of the Doctor seeing the spontaneous writing on the chalkboard when he is in the Tardis is very similar to that of Clara seeing the writing on her chalkboard in Doctor Who: Last Christmas (2014)
13. The Doctor retreats into his "storm room" to figure out solutions to his problems, a similar principle to Sherlock Holmes' "mind palace" in Sherlock (2010) from Who mainstays Steven Moffat and Mark Gatiss, in particular in Gatiss' episode Sherlock: The Hounds of Baskerville (2012).
14. First penultimate episode of Steven Moffat's tenure not to feature the Cybermen.
15. The Doctor says that the person being interrogated is the only irreplaceable person in the room and that when you are threatened with death, "Show them who's boss. Die faster." This is the same approach he used to escape being trapped in the Big Brother house in Doctor Who: Bad Wolf (2005)
16. As he walks down the corridor, the Doctor says to his unseen adversary "the Doctor will see you now". The Eleventh Doctor shouts this same line to the Atraxi in Doctor Who: The Eleventh Hour (2010).
17. The Doctor mentioned that the stool fell out the window for seven seconds. Assuming the local gravity and atmospheric density are the same as Earth, this would give a height of 24.5 metres or 80.38 feet
18. The Doctor mentions that his best friend (Clara) has just died. Missy claimed previously that she received the Doctor's confession dial since she was the Doctor's closest friend and not Clara.
19. The Veil is played by Jami Reid-Quarrell, who previously played Colony Sarff in Doctor Who: The Magician's Apprentice (2015)/Doctor Who: The Witch's Familiar (2015).
20. The Doctor's story that he tells in the beginning is written on a wall in the old castle. Only certain parts are missing.
21. The Doctor says each cycle is 82 minutes. In part one he tells a young boy to remember the number 82.
22. The Doctor wondered if "the birds are here" when he saw the word "bird" written in the castle. Peter Capaldi has previously done an audio book of "The Birds" by Daphne Du Maurier which is the basis of the Alfred Hitchcock movie The Birds (1963) which coincidentally came out the year that Doctor Who started.
23. The Doctor says that "the stars are all in the wrong places," and in fact they do move. When the Doctor faces the camera and comments that it seems that he's traveled 12,000 years into the future there are three bright stars visible in a crooked line over his left shoulder, with a dimmer star in between the top two stars. At 600,000 and 1,200,000 years, the dim star is in the same location. But at 2 million years it appears to have moved slightly to the left, and has moved even further at 20 and 52 million years until it no longer is visible.
24. The Doctor said he'd arrived in Gallifrey "the long way round". In Doctor Who: The Day of the Doctor (2013), the Eleventh Doctor said he was going "Home, the long way round."
25. This is one of only three stories in the history of Doctor Who which don't include a true companion for the Doctor. Doctor Who: The Deadly Assassin: Part One (1976) (1976) was set between the departure of Sarah Jane Smith and the arrival of Leela; in Doctor Who: Midnight (2008), the Doctor goes on a tourist excursion on his own while Donna (who makes a brief appearance in the episode coda) stays behind; and in this story, the Doctor has just lost Clara (she makes brief appearances in his imagination, but is otherwise not involved in the story's narrative). Ironically, this story ends on Gallifrey, which was also the setting for "The Deadly Assassin".From a dramatic standpoint, the role of the companion is generally to act as an audience surrogate (giving the Doctor someone to explain strange technology or situations to, allowing for exposition). Because that role is not filled in this story, the Doctor spends most of the episode talking to himself (in his imagination, this sometimes appears as talking to the TARDIS or Clara).
26. Like the TARDIS and Time Lord art before it, the Doctor's confession dial is revealed to be Time Lord technology that is "bigger on the inside".
27. Prior to the broadcast of Series 8, Steven Moffat stated in interviews that he had already worked out the cliffhanger for the penultimate episode of Series 9, and was quoted as saying "you won't see it coming." The Doctor says almost those exact same words before jumping out the window in this episode, the penultimate episode of Series 9 which does, indeed, lead to a major cliffhanger.
28. The plot involves more fairy story tropes than just the diamond mountain. The Doctor mentions that he's following a trail of breadcrumbs laid out for him, and also the word "bird" is a key plot point. In the fairy story "Hansel and Gretel" by the Brothers Grimm, the children leave a trail of breadcrumbs that they hope will guide them back to safety. However a bird keeps the children trapped in the woods by eating the bread crumb trail. The self-cleaning rooms in the castle erase the trails that the previous Doctors left (such as the bloody footprints in the hallway), requiring him to find convoluted ways to leave clues to help his future selves.
29. There is a very subtle clue in the opening scene as to the identity of the person activating the teleporter. Immediately after the bloody hand pulls the lever, someone groans (the Doctor's voice, but it's ambiguous). Just as the hand lets go, the person falls in the background of the shot. It is in deep shadows and only visible for a few frames, so it is easy to miss. When frozen there is just enough detail to tell that it is a gray-haired person wearing a dark coat with a white shirt.
30. This is one of the few episodes where the actual TARDIS never makes an appearance. Although the Doctor several times seems to be in the console room of the TARDIS, each time it is discovered that he was just envisioning the "storeroom" in his mind to solve a problem and picturing himself back in the TARDIS.
31. The conclusion of this episode reveals the long-awaited return of Gallifrey.
32. On why "the wall" doesn't repair itself: It it generally assumed that the wall isn't part of the castle itself. Steven Moffat once stated, the doctor didn't know for sure that it could be damaged over time, but he could assume as much from the fact that it was a very thick wall. If it would repair itself, a normal wall would suffice. Also, from being able to leave at least some clues behind, the doctor had already figured out that the repair mechanism doesn't cover everything.
33. The premise is similar to that of a script Steven Moffat mentioned he once considered pitching as a Big Finish Audio story with the Eighth Doctor: The Doctor being stuck alone with a threat that preys on his fears.

Hell Bent

1. The four knocks the Doctor hears are the same as the sound of drums the Master heard in the third series, and a reference to the four knocks that Wilf inadvertently used to kill the Tenth Doctor in Doctor Who: The End of Time: Part Two (2010).
2. The Doctor is told to put down all his weapons and he places his spoon on the table. In Doctor Who: Robot of Sherwood (2014) he uses a spoon as a weapon when fighting Robin Hood.
3. In Doctor Who: The Magician's Apprentice (2015) Missy says "Since always. Since the Cloister Wars. Since the night he stole the moon and the President's wife. Since he was a little girl. One of those was a lie. Can you guess which one?"In this episode the Doctor tells Clara "Ah, well, that was a lie put about by the Shobogans. It was the President's 'daughter'. I didn't steal the moon, I lost it..."This implies that the Doctor's first wife, or possibly his granddaughter Susan, was the President's daughter.
4. The brand-new TARDIS' control room interior is re-used from An Adventure in Space and Time (2013).
5. This story marks a unique time that the Doctor fires a weapon at a person in both series. In some storylines the Doctor refuses to even touch a gun.
6. Ken Bones returns as The General, who was last seen in Doctor Who: The Day of the Doctor (2013).
7. Steven Moffat talked about the final two-parter of season 9 with Doctor Who Magazine and said "Episode 11 pushes the Doctor to the brink of madness, and Episode 12 is what happens next. If the Doctor has lost his moral compass, if he's being selfish, if you really, really hacked him off, if you really got him angry and gave him nothing to fight for.. what would you end up with? That's the 'hellbent' of the title. An angry, off-the-rails Doctor."
8. As of 2015, this is the only series finale to have a "next time" trailer.
9. Clara uses the phrase "reversed the polarity" in modifying the memory wiping device; this is a phrase commonly associated with the Third Doctor, but has been used by other Doctors as well.
10. The Doctor uses the term "Space Glasgow", but previously complains when Clara uses the term "Space restaurant" and says "never put the word space in front of something just because everything's all sort of hi-tech and future-y."
11. As this episode takes notes from Sergio Leone's 'spaghetti westerns,' the leit motif - the seven notes - repeatedly heard in The Good, the Bad and the Ugly (1966), which have since become iconic, are heard.
12. Timothy Dalton was unable to reprise his role as Rassilon from "The End of Time" due to his commitment to Penny Dreadful (2014).
13. The Ninth Doctor's theme from Series 1 makes a surprise return, after not being heard since Series 2 in its original format or Series 4 in its adapted form as the Tenth Doctor's theme.
14. Although the episode is officially considered the second part of the story begun in Doctor Who: Heaven Sent (2015), narratively it is the third chapter of a trilogy that begins with Doctor Who: Face the Raven (2015).
15. When the Doctor first enters the diner, "Don't Stop Me Now" sung by Foxes is playing - same version from season 8's Doctor Who: Mummy on the Orient Express (2014).
16. This episode marks the first televised appearance of an interior shot of a TARDIS other than the Doctor's since Time and the Rani, the latter being the Rani's. It is only the second TARDIS control console seen other than the Doctor's since Time and the Rani, after the Junk TARDIS in Doctor Who: The Doctor's Wife (2011).
17. The tune played by the Doctor when he was sitting in the diner is a simplified version of Clara Oswald's theme from the Series 7-9 soundtracks. It is a rare example of a piece of incidental music composed for Doctor Who becoming part of its in-universe narrative. The Doctor says he believes the song is called "Clara". "Clara?" is the name of the track on the Series 7 soundtrack, though it has also been performed at the Proms and other events as "The Impossible Girl" and was titled "Clara and the TARDIS" on the soundtrack for Doctor Who: The Snowmen (2012), which featured the first appearance of the melody. In the context of the story, it is implied that the melody represents the now-forgotten words Clara says to the Doctor in the Cloisters; this is supported by the fact the same piece of music plays (in a full orchestral version) when the episode cuts away from the couple as Clara begins to speak.
18. After the General is shot, the Doctor mentions that, "...death is Time Lord for man-flu." When the General regenerates she comments that she is usually a woman, and the previous incarnation was an aberration and her only time as a man. Thus by dying and regenerating back to a woman, she got over the "man-flu".
19. Although they only receive a brief cameo, the inclusion of the Cybermen ensures the continuation of a pattern that has been ongoing since Series 5, whereby they appear in every twelfth episode of a series.
20. Donald Sumpter previously appeared as two different characters in the original Doctor Who (1963): Enrico Casali in Doctor Who: The Wheel in Space: Episode 1 (1968) and Commander Ridgeway in Doctor Who: The Sea Devils: Episode Three (1972). He also appeared on the now-finished spin-off The Sarah Jane Adventures (2007) in the episode The Sarah Jane Adventures: The Eternity Trap: Part 1 (2009) as Erasmus Darkening.
21. The "Nevada Desert" scenes are taken in Fuerteventura.
22. This story marked the first mention of the Web of Time in the revived series.
23. When told to lay down weapons on his person the Doctor subsequently puts his spoon down. The Doctor once had a duel against Robin Hood with a spoon.
24. Jami Reid-Quarrell returned as a Wraith, after previously playing Colony Sarff in Doctor Who: The Magician's Apprentice (2015)/Doctor Who: The Witch's Familiar (2015), as well as the Veil in Doctor Who: Heaven Sent (2015).
25. You can hear the sound effect of a TIE fighter from Star Wars at 17:30.
26. Rachel Talalay also directed the series 8 two-part finale, Doctor Who: Dark Water (2014) and Doctor Who: Death in Heaven (2014).
27. This is the first episode since "The End of Time" to feature Rassilon.
28. The TARDIS that the Doctor steals to hide at the end of the universe, ends up stuck as a restaurant when Clara and Ashildr leave with it. Douglas Adams, author of the book "The Restaurant at the End of the Universe" was also a writer for the original Doctor Who series.
29. This marks the first time a television episode has had the minor expletive "hell" in the title. The word previously appeared in the titles of the comic stories A Cold Day in Hell! and The Road to Hell as well as the audio story Minuet in Hell.
30. The Radio Times programme listing was accompanied by a small colour head-and-shoulders shot of the General, with the accompanying caption "Doctor Who / 8.00 p.m. The General (Ken Bones) prepares for battle in the series finale".
31. The Wraith are also a alien race in Stargate Atlantis.
32. In the final scene, the Doctor gets rid of the sonic sunglasses and gets his own sonic screwdriver. We also see the return of him snapping his fingers to close the TARDIS doors.
33. The diner looks like the one seen in Doctor Who: The Impossible Astronaut (2011), although the Doctor notes it isn't in the same location. This is revealed to be because it is the outer shell of a TARDIS.
34. When the Doctor decides to wipe Clara's memory of himself to save her, he mentions that he's done it before, telepathically, referring to the Tenth Doctor's wiping Donna Noble's memory of him and her travels in the TARDIS in Doctor Who: Journey's End (2008).
35. the interior of the stolen TARDIS is based on the interior seen in the "classic" series (Doctor Who (1963)), including the scanner screen, white "roundel" walls, and interior doors. The console used is the replica that was rebuilt for the anniversary special An Adventure in Space and Time (2013). The exterior of the TARDIS is an "undisguised" one, as previously seen in Doctor Who: The Name of the Doctor (2013).
36. First appearance of the Weeping Angels since Doctor Who: The Time of the Doctor (2013).
37. The TARDIS that the Doctor and Clara steal to escape the Cloisters is modelled in its interior on the original TARDIS from the original series as seen in Doctor Who: An Unearthly Child (1963).
38. The Doctor, once on Gallifrey, travels to the same barn on the Dry Lands where he spent time as a child, as seen in Doctor Who: Listen (2014), and would later be where he debates the use of the Moment in Doctor Who: The Day of the Doctor (2013).
39. The "sad song" the Doctor plays is "Clara's Theme" by Murray Gold.
40. Steven Moffat made repeated statements that Clara would never be able to return to the series after the events of the finale. Obviously, she can as long as she does so before returning to Gallifrey to face the raven.
41. In an interview, Sarah Dollard said how sad she was that Clara couldn't get a TARDIS of her own and run off with lady-friend Jane Austen. Lack of famous author aside, that's exactly what Clara's final end was.
42. For most of the history of the series, Rassilon was established as the long-dead founder of the Time Lords (and co-discoverer, with Omega, of time-travel). In this story, Donald Sumpter plays President Rassilon, and refers to himself as 'Rassilon the Ressurected' - a confirmation that this is intended to be the *original* Rassilon, presumably resurrected (like the Master) for the Time War. His appearance has changed several times (the last appearance Rassilon made was in Doctor Who: The End of Time: Part Two (2010), portrayed by Timothy Dalton), but as a Time Lord, he certainly has the ability to regenerate.
43. Before deciding that the Doctor and Clara, combined, are the Hybrid, Ashildr postulated that the Doctor might be half-human and thus the Hybrid. The Eighth Doctor made a similar statement about his lineage in Doctor Who (1996).
44. This is the first television story to actually show a regeneration from a male body to a female. There have been references to this having happened with the Corsair (Doctor Who: The Doctor's Wife (2011)) and the Master (Doctor Who: Dark Water (2014)/Doctor Who: Death in Heaven (2014)), and it was one of the options the Eighth Doctor received in Doctor Who: The Night of the Doctor (2013), but it has never been featured on a televised story until now, in this case the General from his eleventh to twelfth incarnation. It also shows the first change of skin colour from white to black. The first incident was of Melody Pond to Mels, but the change was never seen, but the change the other way around was seen in Doctor Who: Let's Kill Hitler (2011).
45. Previously in Doctor Who: Death in Heaven (2014) the Doctor previously told Clara that he would "never again" steal a Tardis and run off. He goes back on his word on many other things here, including that.
46. This episode confirms that Time Lords can change sex when they regenerate. It was first mentioned in relation to the Corsair in Doctor Who: The Doctor's Wife (2011) and is, presumably, the reason the Master is now Missy, but this is the first time such a change occurs on-screen: the General changes from a man to a woman and the says that she is usually female.
47. In the episode "Journey's End"(4.13), the Doctor/Donna is said to be a half Timelord-half human hybrid, possibly the one prophecies said would bring about the end of Gallifrey as she is also a "product of two warrior races."

The Husbands of River Song

1. Among the items River Song removes from her bag to make room for the head is a red fez.
2. Steven Moffat intended for a while to have this be his last episode before passing the show to a new runner, hence his using it to finally tie off his very first original plot thread. Then he decided at the last minute to stay a while longer.
3. This is the first episode where both the Doctor and his companion are played by people over the age of 50.
4. River carries a sonic trowel. While this reflects her profession as an archaeologist, it is also something of a family tradition: her grandfather, Brian Williams (the father of companion Rory Williams), always carried a trowel.
5. The Doctor says he needs a flowchart to keep track of his relationship with River and a number of fans have already constructed such diagrams for that very purpose.
6. The Doctor says that River was once married to Stephen Fry. Fry has a long history with the show, going back to before its revival. He provided the voice of a character in the animated mini-series Doctor Who: Death Comes to Time (2001) and once wrote an episode during the Russell T. Davies era but it required rewrites to make the budget more manageable and he couldn't do them in time (the slot was taken by Doctor Who: Fear Her (2006), which, at the time of this episode's broadcast, was the joint lowest-rated episode of the new series).
7. The Doctor uses both of River's catchphrases - "Hello sweetie" and "Spoilers". In addition he is delighted to finally get the chance to pretend to be new to the TARDIS and proclaim that "it is bigger on the inside".
8. When the Doctor argues about River's "marriages", River recounts some of the Doctor's own: Elizabeth I (Doctor Who: The Day of the Doctor (2013)), Marilyn Monroe (Doctor Who: A Christmas Carol (2010)), and possibly Cleopatra.
9. Steven Moffat has spoken about the episode and said: "That's been a riot to do. That's been sort of a big fun chase episode, really. Just Mr and Mrs Who battling their way past nonsense and that's been great fun. Alex [Kingston] is always great value."
10. As he reads River's diary, Flemming relates many of her adventures with the Doctor: the opening of the Pandorica (Doctor Who: The Pandorica Opens (2010)), the crash of the Byzantium (first mentioned in Doctor Who: Silence in the Library (2008) and shown in Doctor Who: Flesh and Stone (2010)), a picnic in Asgard (Doctor Who: Silence in the Library (2008)), an encounter with Jim the Fish (Doctor Who: The Impossible Astronaut (2011)), and her most recent trip - to a place called "Manhattan" (Doctor Who: The Angels Take Manhattan (2012)).
11. When arguing about each other's past relationships, River brings up Cleopatra, to which the Doctor responds "Same thing!". River mentions seducing Cleopatra, whom she describes as "a real pushover", in "The Wedding of River Song". She also posed as Cleopatra in "The Pandorica Opens".
12. In early 2016, it was announced Matt Lucas would return as Nardole in Series 10 as another new companion of The Doctor and would join newcomer Pearl Mackie opposite Peter Capaldi.
13. Prior to appearing in this episode as Nardole, Matt Lucas guest starred on the American series 'Community' as a die hard fan of "Professor Space Time," which is a parody version of 'Doctor Who.'
14. The Doctor is heard to say "when the wind stands fair and the night is perfect, when you least expect it, but always when you need it the most, there is a song". Though he is referring to the Singing Towers in this context, his statement could also apply to River herself, either symbolically or as a compliment. This is due to his inclusion of the word "song", which is her last name. Moreover, "song" is another name for "melody", which the towers produce; River's birth name is Melody Pond, and her alternate name, River Song, is the result of her birth name being translated into the language of the Gamma Forests, seen in Doctor Who: A Good Man Goes to War (2011).
15. River says that the Twelfth Doctor reminds her of her second wife, which later led to fan speculation that the wife in question may be (unbeknownst to River), the Thirteenth Doctor, who is played by actress Jodie Whittaker.
16. When River says of her diary "One should always have something sensational to read on the spaceship" she is paraphrasing Gwendolen from Oscar Wilde's 'The Importance of Being Earnest' who said a similar thing, but of a train, not a spaceship.
17. River's pictures of the Doctors are screencapped from The Green Death, The Deadly Assassin, The Caves of Androzani, The Two Doctors, Doctor Who (1996), Doctor Who: The Doctor Dances (2005), Doctor Who: Tooth and Claw (2006), and Doctor Who: The Day of the Doctor (2013), with the episodes for the First, Sixth and Seventh Doctors unidentifiable, some of which might potentially be digitally photo-edited pictures created using archive images of the Doctors.
18. This is the first time in a main story that Alex Kingston's name has appeared in the opening titles.
19. When River is naming all the women The Doctor was involved with, she mentions Cleopatra. In Doctor Who: The Pandorica Opens (2010), River Song pretends to be Cleopatra. An earlier incarnation of The Doctor had a relationship with the Egyptian Queen and was mentioned by Mickey Smith in Doctor Who: The Girl in the Fireplace (2006).
20. A variation of The Doctor's Theme is played when River and Ramone discuss the "Damsel in distress".
21. The little town set used for Mendorax Dellora appears to have been repurposed from the trap street set used in Doctor Who: Face the Raven (2015).
22. This is the first time outside of mini-episodes that River has been in a story not to feature one of the Doctor's companions alongside her and the Doctor.
23. This is the first episode since Doctor Who: The Angels Take Manhattan (2012), and the first starring Peter Capaldi, to not feature Jenna Coleman as Clara Oswald.
24. As Mels, River used the phrase "penny in the air" when someone was oblivious to something important, following up with "and the penny drops" when they finally figured it out, seen in Doctor Who: Let's Kill Hitler (2011). Ironically, River is guilty of becoming the butt of her own joke for being oblivious to the fact that the Doctor is right in front of her until it is made indubitable.
25. The 2nd Christmas special which The Doctor is aboard a space passenger liner. The 1st was Doctor Who: Voyage of the Damned (2007) (TV Episode).
26. Various references to River Song's past with the Doctor are scattered about. Amongst them are her blue 'call box' diary.
27. Nardole's woolly hat and coat are almost identical to the woolly hat and coat worn by Stan Marsh in "South Park".
28. Rowan Polonski is dubbed by Silas Carson.
29. Chris Lew Hum Hol is dubbed by Philip Rhys.
30. No cast details accompanied the programme listing in Radio Times, which had the synopsis "When a crashed spaceship calls upon his help, the Time Lord finds himself launched on a chase across the galaxy. Greg Davies and Matt Lucas guest-star." However, the listing for the repeat on Boxing Day (26th December) included a cast list as well the same synopsis (but excluded the final sentence).
31. Robert Curtis is dubbed by another actor.
32. In Doctor Who: Forest of the Dead (2008), the Doctor and River's next and final meeting (in her timeline), she says "The last time I saw you, the real you, the future you, I mean, you turned up on my doorstep, with a new haircut and a suit. You took me to Darillium to see the Singing Towers. What a night that was. The Towers sang, and you cried. ... You even gave me your screwdriver."Most of this happened by the end of this episode. The earlier quote is even referenced when they meet, as River asks "Nardole, what have you brought to my doorstep?" To which the Doctor replies "I've had a haircut. This is my best suit." The only difference is that, while he did give her a sonic screwdriver, it wasn't his own one, the Doctor had made a new one for River.
33. The Sonic Screwdriver the Doctor gives River is the same River will have in the 4th Season "Silence in the Library" 2-parter. This episode marks the end, potentially, of River's timeline, at least the main line leading up to when River sacrifices herself in order to save the Doctor. The episode alludes to the Doctor and River's last night together, which means River will eventually call on the Doctor, via the psychic paper which summons the 10th Doctor and Donna Noble to the Library.
34. When the Doctor gives River the sonic screwdriver, he turns it on and waves it in her general direction. While this looks like a simple playful act, he is in fact scanning her so her soul will be stored in the device, enabling the Tenth Doctor to save her in the Library's computer during "Silence in the Library". This creates a closed time loop, also known as a predestination paradox, as the Twelfth Doctor only knows he must do this because of his previous memories as the Tenth Doctor.
35. Details of the Doctor's last encounter with River at the singing towers of Darillium, originally mentioned in Doctor Who: Forest of the Dead (2008), are shown here. The Doctor says that he has just had a haircut and is wearing his best suit ("You turned up on my doorstep, with a new haircut and a suit"). As the towers sing, the Doctor sheds a tear ("Oh, what a night that was! The towers sang and you cried"), and he refuses to tell her that this is their final night together before her death ("You wouldn't tell me why, but I suppose you knew it was time. My time.") River mentions that the Doctor had postponed it several times, one of which was shown in the mini-episode Last Night.
36. The Doctor uses both of River's catchphrases - "Hello, Sweetie" and "Spoilers". River's last line to the Doctor is "I hate you", to which the Doctor replies "No, you don't". This is banter River and the Eleventh Doctor often used, such as in Doctor Who: The Impossible Astronaut (2011).
37. When River's sonic screwdriver is revealed as her present, an excerpt of the Series 4 soundtrack "Silence In The Library" is heard, foreshadowing the events to come in River's last adventure.
38. While this story offers closure to River's life, Alex Kingston later suggested she might return to the role to guest star alongside the first female Doctor, played by Jodie Whittaker.
39. In "Let's Kill Hitler", the newly regenerated River Song remarks that she "might take the age down a bit", explaining why her apparent age is not consistent with her timeline. From River's point of view, this story takes place just prior to her death in "Silence in the Library/The Forest of the Dead", which means that in the twenty-four years she spends with the Twelfth-Doctor, she goes from the oldest she's ever looked, to the youngest she's ever looked.
40. The Doctor tells River that "every Christmas is last Christmas", repeating what a dream-image Danny Pink tells Clara Oswald in Doctor Who: Last Christmas (2014).
41. In 2016, it was announced showrunner and River Song creator Steven Moffat is leaving the series and that "Broadchurch" creator Chris Chibnall would take over. (#10.0) takes place just before River Song's death in Forest of the Dead (#4.9). It's most likely, if River Song does not return again in the Chris Chibnall era, the 2015 Christmas Special may very well be Alex Kingston's final appearance as River Song and that the character of River Song will very much be retired.
42. The final appearance of Alex Kingston as River Song. In early 2016, Steven Moffat announced that he was leaving Doctor Who (2005) and Chris Chibnall is set to take over as showrunner. With Moffat, who created the character of River Song, leaving the series, River Song will be retired. River Song died in Doctor Who: Forest of the Dead (2008) and it's assumed Doctor Who: The Husbands of River Song (2015) takes place before Doctor Who: Forest of the Dead (2008) because The Doctor gives River Song her own Sonic Screwdriver.
43. First appearance of River Song since Doctor Who: The Name of the Doctor (2013).
44. The first appearance of Matt Lucas as Nardole. In early 2016, it was announced that Matt Lucas would return as a full time companion opposite Peter Capaldi and newcomer Pearl Mackie as Bill and Matt Lucas was spotted on the set of Series 10 in his costume from Doctor Who: The Husbands of River Song (2015). Nardole returned in the 2016 Christmas special, having been given his own cybernetic body, and later appeared in Series 10 as a full-time companion.
45. Gary Russell previously attempted to have the Twelfth Doctor and River meet in his novel Big Bang Generation, but as Steven Moffat set this special up to be the Twelfth Doctor's first, last and only meeting with River before she sacrificed her physical body, Russell chose to replace River with Bernice Summerfield in the story.