Death in Heaven (TV story)

Death in Heaven was the twelfth and final episode of the eighth series of Doctor Who produced by BBC Wales. It saw the second death of Danny Pink, the death of one of the two Osgoods, and the apparent death of the Master.

It revealed that Missy had been the "woman in the shop" who gave Clara the TARDIS phone number in The Bells of Saint John and the one who had provided the advertisement that drew the Doctor and Clara together again in Deep Breath.

It also allowed Doctor Who to again pay homage to the late Nicholas Courtney, with his character, the Brigadier, appearing as a Cyberman. This was the first televised Doctor Who appearance by the character since Battlefield, and effectively his first televised appearance since Courtney's death. He had appeared in audios and The Sarah Jane Adventures in the intervening time period.

Death in Heaven, and first-part episode Dark Water, was shown in cinemas in 3D as a two-night event on the 15th and 16th September as a run-up to prepare for Series 9. It was followed by the premiere of the prequel scene The Doctor's Meditation. This screening was only shown in the United States of America, Canada, Denmark and Russia.

Synopsis
With Cybermen on the streets of London, old friends unite against old enemies and the Doctor takes to the air in a startling new role.

Can the mighty UNIT contain Missy? As the Doctor faces his greatest challenge, sacrifices must be made before the day is won.

Plot
Inside the 3W facility, a Cyberman detects Clara. She advises that she should be kept alive, as she is a target of strategic value. The Cyberman scans her, and states that she is Clara Oswald. Clara denies this, then begins to list attributes of the Doctor. The Cyberman demands she identify herself. She claims that Clara Oswald never existed: she is the Doctor.

Outside of St Paul's Cathedral, advertises the Cybermen as big metal men and charges the public one pound for a picture with them. She reveals that the same thing is happening globally. An undercover Osgood offers to take a picture, and after seizing Missy's weapon, UNIT officers reveal themselves from the crowd. The Cybermen use their rocket boots to escape. The roof of St Paul's opens and more fly out.

Missy reveals that there are ninety-one Cybermen. Osgood states that this is the number of areas of significant population densities in the British Isles, meaning one Cyberman for every town and city in the world. One Cyberman detonates itself above St Paul's, creating a dark cloud and deploying Cyber-pollen.

Meanwhile in the Nethersphere, all the lights go out. Seb tells Danny that they all might be going home. He explains to Danny that he should think of the Nethersphere as a data-cloud for storing recently deceased minds. The good news, he says, is that their bodies have been "upgraded".

Back at St Paul's both Missy and the Doctor are sedated and the Doctor just manages to whisper to Osgood, "Guard the graveyards" before passing out. Kate Lethbridge-Stewart states on the phone that the "first protocol" has been implemented as the cloud made by the Cyberman starts to rain into the graveyards – and only the graveyards. The water seeps out and makes the sewers and gutters overflow. The water gets into the Chaplet Funeral Home and animates the newly converted Cybermen within. One of these is revealed to be Danny Pink, who clutches the sheet of paper with his information on it.

Meanwhile, the Doctor wakes up in a UNIT aircraft hanger with the TARDIS as Kate informs him that protocols are in place and his co-operation is to be ensured, since UNIT assumes that he won't automatically do so. The Doctor asks for Clara and Kate says that he just has to give the order, as soon as he is on the plane his word is literally law. The plane is revealed to be Boat One. Kate tells someone on the phone that the President is aboard and when the Doctor comments on the uselessness of Americans, Colonel Ahmed reveals that the President of the United States was not being referred to; instead they were talking about the newly inaugurated President of Earth, commander in chief of all armies on the planet with complete authority in every nation — the Doctor himself!

Back in St Paul's, Clara displays an incredible knowledge of the Doctor, trying to convince the Cybermen that she is him. She even offered to reveal his true name, however another Cyberman arrives telling the other three both the lie and its cause. He looks down when she says that she is an incredible liar. He then knocks her unconscious and kills the other three who realise that he is not under Cyber-control. He is revealed to be Danny.

As Missy wakes up, the Doctor asks her why she is alive and she states that he saved her, with Gallifrey being collateral damage. She then reveals that she knows where it is but refuses to give him this information. As he leaves the Doctor reminds her of all those times she wanted to rule the world and calls it a piece of cake. Osgood quickly guesses who Missy is and brings the Cyber-clouds to the Doctor's attention, specifically the fact that they have expanded and now cover all land-masses. In response, the Doctor offers her a position in the TARDIS. It is revealed that Cybermen have been climbing out of graves the world over.

When Clara wakes up, she finds herself in a graveyard just as Cybermen start climbing out of their graves.

On Boat One, a council discusses the graves, finding that though only a handful of Cybermen had come out yet, many more were hatching. The Doctor realises that the entire point of the 3W organisation was to learn how to Cyber-convert the dead, and is very pessimistic of the chances of stopping them now they have this new ability.

Meanwhile all the Cybermen in the graveyard that Clara is in are fully out as they wander aimlessly.

On board Boat One the Doctor notes that these new Cybermen are not attacking since they are newborns. Kate reveals that they had been investigating 3W for a while, before they got a tip-off from a woman with a Scottish accent – Missy, the Doctor guesses. The Doctor reveals that Missy has been uploading minds in the Nethersphere for as long as humanity has had a concept of an after life.

While this is happening, Missy attempts to gain Osgood's attention by singing a version of "Hey, Mickey" replacing Mickey with Missy. She whispers a secret in her ear in a distinctly Scottish accent — "I'm going to kill you in a minute." She refers to this as her "secret girl plan". She starts a countdown from ten, while mocking human lifespans, before revealing that she had already escaped her restraints. She then kills her guards and Osgood before thanking her for being 'yummy'. She presses a button on her bracelet which causes a horde of flying Cybermen to attack the plane.

In the graveyard, Clara finds the one that brought her there and says that the Doctor is the one man that she would never lie to. At this point, the Cyberman tries to shoot her but cannot. Instead he takes his mask off and reveals himself to be a highly mutilated Danny, who asks her to turn on his emotion inhibitor.

Meanwhile, back on Boat One, Missy prompts the Doctor to ask her about her plan, promising that he will be surprised. She claims that by investigating those that die to save him she has realised that he wants to know that he is like her. The TARDIS phone begins ringing and Missy reveals that she both gave Clara the TARDIS' phone number (pretending it was for a PC helpline), and placed the advert in the Victorian newspaper. She claims that it was the only way to make sure the two deeply-opposite personalities — a control freak and a man who can never be controlled - stayed together.

The Doctor answers the TARDIS phone; Clara has called to tell him about Danny. He warns her not to turn on the inhibitor, because Danny will revert to a Cyberman and kill her if she does. Meanwhile, the Cybermen are breaking into Boat One and killing crew members. Clara begins to hit switches around Danny's power core, hoping to find the inhibitor switch.

On Boat One, Kate has alerted other organisations of their situation and rushes into the room, saying that the plane is going down. Missy turns her attention to her and says that she likes Kate before blowing out a section of the wall, sucking her out of the plane. She orders the Cybermen to destroy the plane and teleports away, leaving the Doctor.

Boat One explodes and the Doctor is thrown clear of the debris. Seb and Missy watch on from the Nethersphere, remarking on how boring his death will be. Using his key to summon the TARDIS, the Doctor manages to catch and enter his ship before reaching the ground. Seb is excited over the turn of events, to which Missy replies that Seb is merely an AI. Seb continues to be enthusiastic before Missy promptly destroys him. The Doctor materialises in the graveyard and warns Clara that if she deletes Danny's emotions, he will kill her. He denies that he will, and the Doctor says that the difference between himself and Missy is emotion. He tries to get Danny to tell him what the cloud will do, but Danny says he isn't fully integrated into the Cyber hivemind and cannot see, mocking the Doctor as a typical officer who has to keep his hands clean.

Clara takes the Doctor's sonic screwdriver and enables Danny's emotional inhibitor. He tells the Doctor that the cloud will convert all of humanity into Cybermen.

Missy then teleports into the graveyard, demonstrating her full control of the Cybermen now assembled. She then gives the Doctor a bracelet, allowing him the same control, as a birthday gift — "It's lucky one of us remembers," she notes — and says that he can save everyone he wants to save and right all the wrongs in the universe.

He refuses control of the army, demanding to know why she is doing this. Missy says she wants to show him that they are not so different, and that she needs her friend back. After remembering how he had wondered if he was a good man, the Doctor realises something and thanks Missy for helping him. He declares he is not a good man, nor a bad man, nor a hero, nor a president, nor an officer (as Danny had described him). He says that he is "an idiot, with a box and a screwdriver, passing through, helping out, learning".

He says he does not need an army, and throws the bracelet to Danny — which he has realised was the only Cyberman who had not obeyed Missy's orders — who puts it on and assumes control of the Cybermen. He promises Clara that she will "sleep safe tonight" before flying into the cloud with the rest of the Cybermen and destroying it, himself and the other Cybermen.

In the graveyard, Missy recites the coordinates of Gallifrey, claiming it has returned to its original location. Clara threatens to kill Missy with her own weapon; the Doctor takes it from her and prepares to do it himself to spare Clara. Before he can, however, a blast from behind them hits her, seemingly disintegrating her.

A Cyberman is behind them. It lowers its weapon and points toward another section of the graveyard; Clara sees Kate Stewart lying there, still alive, muttering about her father.

The Doctor, now understanding, turns back to the Cyberman, who he realises is Brigadier Lethbridge-Stewart, and remarks, "The Earth's darkest hour, and mine. Where else would you be?" before saluting him — Kate had previously remarked that her father's greatest wish had been to receive a salute from the Doctor. The Cyberman Brigadier then flies up into the sky, with the Doctor whispering "Thank you" after him...

Two weeks later, Clara awakes in the middle of the night to find a portal to the Nethersphere in her hallway. Danny speaks through it, saying that the Nethersphere is collapsing and that the bracelet only has enough power left for one one-way trip. Instead of coming through the portal himself, however, he sends through the young Afghan boy he killed, telling her to find his parents. He says is sorry and the portal closes, leaving the boy in the hallway along with the broken bracelet.

The Doctor meets Clara in a restaurant, the latter remarking that he is two weeks late (an apparent improvement compared to previous errors). He notes she is wearing the bracelet and assumes Danny has returned from the Nethersphere; she tries to tell him he hasn't, but he thinks she is trying to say that she can't travel in the TARDIS anymore.

He says that it is fine, and that he has found Gallifrey exactly where Missy said it was, and that, "for once, she wasn't lying". In fact, it is revealed that the Doctor travelled to the coordinates Missy gave him and found nothing but empty space. Closing the TARDIS door, he entered a fit of rage and attacked the console before sinking to the floor and weeping for his lost home planet. At the end of the day, Missy has had the last laugh.

However, the Doctor lies to Clara, telling her he found Gallifrey to make her believe that he will be fine without her. Hearing this, Clara changes her mind and goes along with the Doctor's belief that Danny has returned and that she too will be happy without the Doctor. Clara asks what he will do now; he says that Gallifrey can be a good place and that he will try to make it one. He says it's a long commute and Clara and Danny mightn't be able to make it.

They leave with a hug. Clara asks why he doesn't like hugging and he responds, "Never trust a hug. It's just a way to hide your face." As they hug, their faces each reveal their sadness behind each other's back. As the Doctor enters his TARDIS, Clara tells him that he made her feel special when they travelled together and thanks him for it. He thanks her "for exactly the same" and dematerialises the TARDIS while Clara walks away.

In a mid-credits scene, the Doctor is brooding alone in his TARDIS when he hears someone knocking at the door, telling him that "it can't end like this" and that neither Clara nor the Doctor is "okay". The voice turns out to be that of Santa Claus, who enters the TARDIS in a swirl of snowflakes and asks a boggling Doctor what he wants for Christmas...

Cast

 * The Doctor - Peter Capaldi
 * Clara - Jenna Coleman
 * Danny - Samuel Anderson
 * - Michelle Gomez
 * Seb - Chris Addison
 * Osgood - Ingrid Oliver
 * Kate Lethbridge-Stewart - Jemma Redgrave
 * Colonel Ahmed - Sanjeev Bhaskar
 * Graham - James Pearse
 * Boy - Antonio Bourouphael
 * Teenage Boy - Shane Keogh-Grenade
 * Teenage Girl - Katie Bignell
 * Cyberman - Jeremiah Krage
 * Voice of the Cybermen - Nicholas Briggs
 * Santa Claus - Nick Frost

Cultural references from the real world

 * Missy descends from the clouds with her umbrella opened, copying the title character in Mary Poppins. In fact, in the Doctor Who Magazine interview  with Peter Capaldi, a taxi-driver passing by during filming whoops that "it's Doctor Who and Mary Poppins!" - Capaldi promptly started singing "Feed the Birds" from that movie.
 * Missy does an impression of Marilyn Monroe singing "Happy Birthday, Mr President".
 * The Doctor calls Valiant "Cloudbase". Osgood immediately says Cloudbase is from Thunderbirds, but Colonel Ahmed quickly corrects her with Captain Scarlet. In addition, the Doctor claims he and Sylvia Anderson, wife of Gerry Anderson, the creator of both shows, shared at least one dance together.
 * The Doctor mocks Colonel Ahmed about being a Man Scout.

Individuals

 * Missy claims that she is giving the Cyberman army to the Doctor as a birthday present.
 * Danny’s body was being stored at the Chaplet Funeral Home, a possible reference to Dodo Chaplet who was a companion of the First Doctor.
 * Kate Stewart declares herself divorced, mother of two children, a "keen" gardener, and an "outstanding" bridge player.

Story notes

 * Clara's ruse to the Cybermen of claiming to be the Doctor in the pre-opening teaser was followed by a one-off modification to the title sequence, with the eyes of the Twelfth Doctor being replaced by those of Clara's, and Jenna Coleman's name preceding that of Peter Capaldi.
 * This is the first and,, only episode where the name of the actor playing the Doctor is not the first name to appear in the title sequence (Jenna Coleman appears first).
 * This is also the second episode to feature any aspect of the face of someone other than the Doctor in the title sequence. The first was the 1996 TV movie, which also featured the eyes of someone else, in that case the Master.
 * The Radio Times programme listing was accompanied by a small colour head-and-shoulders photograph of Missy holding her weapon in her outstretched hand as the Doctor looks on, with the accompanying caption "Doctor Who / 8.00 p.m. Who are you? The Doctor is disturbed by the mysterious Missy in the series finale".
 * To keep the appearance of Santa Claus a surprise, Nick Frost was uncredited in Radio Times and on the BBC website.
 * This is the first episode to show a scene mid-end credits.
 * This is the first series finale to lead directly into the following Christmas Special since Last of the Time Lords.
 * Matt Smith as the Eleventh Doctor appears for a second time since his regeneration in The Time of the Doctor, in archive footage from The Bells of Saint John. He last appeared in Deep Breath.
 * Danny calling to Clara while she sleeps is very similar to the Tenth Doctor calling to Rose Tyler after she is trapped on a parallel Earth. (TV: Doomsday)
 * This is the first reference of the term Prydonian since the 2005 revival of Doctor Who.
 * The episode continues the trend of the Cybermen appearing in each series' twelfth episode ever since Steven Moffat took over as showrunner. They also appeared in The Pandorica Opens, Closing Time and Nightmare in Silver, the twelfth episodes of series 5, 6 and 7 respectively.
 * Steven Moffat stated that Clara's reference to the Doctor being married four times included his marriage to Susan's grandmother. (DWM 482)

Ratings
7.60 million (DWM 481)

Filming locations

 * St. Paul's Cathedral, London
 * Queen Street, Cardiff

Production errors

 * In the BBC iPlayer version of this episode, during the flashback scene featuring Rusty, the subtitles incorrectly credit his lines as being said by Davros.
 * As Missy drops her hat, someone hugs the Cyberman in front of her and squeezes its arm which makes the rubber costume fold in.
 * When Clara is on the phone with the Doctor, telling him about Danny being a Cyberman, the wide shot shows the chest piece that covers the emotional inhibitor on, even though he had already removed it prior.
 * When Missy has the side of the plane blown off, her wrist device is still on. When she tells the Cybermen to blow up the plane over Belgium, it's disappeared, but in the next shot, it's returned to her wrist.
 * When the Doctor prepares to kill Missy, he is clearly holding her device in the wrong orientation, with the beam emitters pointing towards the ground.

Myths

 * This would be Clara's last story. At one point, this was true. Up until shortly before production the plan was for Jenna Coleman to leave the series with this episode, however she decided to return for the Christmas special and Series 9.
 * Clara is pregnant or dying. These two myths/rumours were sparked by the post-it note reading "3 months" seen in Dark Water, with the former also supported by the existence of Orson Pink in TV: Listen who is supposedly a descendant of Clara and Danny, yet Danny is now dead. Ultimately, the significance of "3 months" was never explained.

Continuity

 * Kate presents a damaged Cyberman headpiece to the Cybermen who emerged from St. Paul's Cathedral - a token from a previous attempt at invading Earth. (TV: The Invasion)
 * The Doctor again works with Kate Stewart (TV: The Power of Three) and Osgood (TV: The Day of the Doctor).
 * Missy shares the Doctor's view on human life spans - that they are ridiculously short (TV: The Caretaker); while the Doctor says humans should be "in a constant state of panic", Missy says that humans are "born dying".
 * The Doctor offers to take Osgood with him as a companion, but Missy kills her before he can make good on this promise. This isn't the first time someone was offered the chance to become a companion but died before they could take up the offer. Other invitees who died have included Lynda Moss, (TV: The Parting of the Ways) Madame de Pompadour (TV: The Girl in the Fireplace), Astrid Peth (TV: Voyage of the Damned), Clara Oswin Oswald (TV: The Snowmen) and Rita (TV: The God Complex). The Doctor also offered Jenny, his daughter created via genetic transfer, to become his companion. (TV: The Doctor's Daughter)
 * Missy tells Osgood to "say something nice" shortly before her death. She previously told Dr. Chang to "say something nice" before his death (TV: Dark Water), and when cornered by the Doctor in the graveyard asks him to "say something nice" as she waits for him to shoot her.
 * Osgood has upgraded her attire of Doctor-clothes, now instead of wearing a multi-coloured scarf (TV: Robot to TV: The Horns of Nimon), she wears the Tenth Doctor's converse trainers (TV: The Christmas Invasion et al.) and the Eleventh Doctor's bow-tie (TV: The Eleventh Hour et al.), as well as a leather jacket, worn both by the War and Ninth Doctors.
 * When the Doctor first sees Osgood, he compliments her bowtie with "Nice bowtie". He previously complimented her scarf with "Nice scarf" upon first meeting her. (TV: The Day of the Doctor)
 * When the Doctor compliments her bowtie, Osgood says "bow ties are cool", a phrase he often used in his previous incarnation. (TV: The Eleventh Hour et al.)
 * The last time the Doctor made reference to his predecessor's bowtie, he described it as "A bit embarrassing." (TV: Time Heist)
 * Missy uses the phrase "Oh, my giddy aunt" when she is about to kill Osgood, a catchphrase frequently associated with the Second Doctor. (TV: The Krotons, The Three Doctors, The Two Doctors)
 * Neither Kate Stewart nor Osgood appear surprised at meeting yet another incarnation of the Doctor. (TV: The Day of the Doctor)
 * Osgood reveals that she knows that Missy is the Master, and that she knows that the Doctor and the Master were childhood friends, (TV: The Time Monster, The End of Time, PROSE: The Dark Path) and that the Master had many times tried to take over the world. (TV: Terror of the Autons et.al.)
 * The Doctor later told Danny that he had a friend once that he thought was exactly the same as him, but it turned out to be wrong. (PROSE: The Dark Path et.al.)
 * Missy is tied to a chair while on the airplane. This draws a parallel to the Master previously being tied to a chair in Joshua Naismith's mansion. (TV: The End of Time)
 * The Doctor calls himself an idiot. He previously called himself "Doctor Idiot". (TV: In the Forest of the Night) He also called himself an "idiot" and was thereafter called "idiot" by Panna. (TV: Kinda)
 * Clara asks the Doctor if he will steal a TARDIS and run away again after he goes back to Gallifrey. (TV: The Name of the Doctor) He later does this when he finally returns to Gallifrey. (TV: Hell Bent)
 * The Doctor kisses Missy, who previously kissed him. (TV: Dark Water)
 * The Doctor salutes the Cyber-converted Brigadier. He also twice saluted the Brigadier's daughter, Kate Stewart. (TV: The Power of Three, The Day of the Doctor)
 * The Doctor continues to hate when people salute him, however. (TV: The Sontaran Stratagem et al), though he accepted the Foretold's salute in Mummy on the Orient Express.)
 * Clara uses the identity of the Doctor for the second time. (TV: Flatline)
 * A news report mentions "accounts" on file of earlier appearances of the Cybermen. (TV: The Invasion, Army of Ghosts/Doomsday)
 * The same news report indicates that, prior to this incident, the name "Cybermen" was not actually widely known.
 * Osgood notes UNIT has files on all ex-Prime Ministers in reference to the Master's previous incursion, commenting "she wasn't even the worst". (TV: The Sound of Drums/Last of the Time Lords)
 * Missy reveals that she was the "woman in the shop" from whom Clara received the Doctor's phone number for Wi-Fi support, (TV: The Bells of Saint John) as well as being the one that left the hint in a newspaper which led Clara and the Doctor to ending up in the hideout of the Clockwork Droids. (TV: Deep Breath)
 * While masquerading as the Doctor, Clara claims many things from the Doctor's past, revealing that during her time with the Doctor she has gained intimate knowledge of his history:
 * She notes that among his family is a non-Gallifreyan daughter created via genetic transfer. (TV: The Doctor's Daughter)
 * She mentions the Doctor having children and grandchildren, which would presumably include Susan Foreman (TV: An Unearthly Child et.al.), though she indicates them to be missing, presumed dead. The Doctor previously indicated that he believed his family to be dead. (TV: The Tomb of the Cybermen, Gridlock)
 * She says the Doctor graduated with a doctorate in Glasgow in the wrong century. (TV: The Moonbase) She indicates this to be his only actual doctorate, although this is counter to what the Doctor and others have stated. (TV: The Armageddon Factor, Utopia, The God Complex)
 * He is from the constellation of Kasterborous. (TV: Pyramids of Mars, Voyage of the Damned)
 * He was a Prydonian. (TV: The Deadly Assassin) Clara indicates he lost this status when he stole the TARDIS. This is the first on-screen reference to this aspect of the Doctor's history in the modern era.
 * The Doctor previously claimed to have met Santa Claus, who he called "Jeff". (TV: A Christmas Carol)
 * When Missy states that the Doctor saved her, he says he saved Gallifrey and that it's lost. Missy responds that it's not lost, something that the Curator previously stated it was. (TV: The Day of the Doctor)
 * Missy states that Gallifrey has returned to its original place, with the coordinates of 10-0-11-00 by 02 (TV: Pyramids of Mars, Full Circle); however, it later appears that Missy lied.
 * Missy mentioned all the times she and the Doctor faced each other and the Doctor ask if she remember all the times she tried to dominate the world, before gleefully showing that thanks to her actions he's now President of Earth. (TV: Terror of the Autons et.al.)
 * Santa Claus knocks on the TARDIS' door three times with a rhythm of four, just like Wilfred Mott did when he fulfilled the prophecy, "He will knock four times." (TV: The End of Time)
 * Missy's Cybermen have a hive mind, like the Cyberiad on the Hedgewick's World of Wonders (TV: Nightmare in Silver).
 * In order to save her life, Clara tells the Cyberman she has important information and, alive, she is a tactical advantage. Rose Tyler used a similar argument to save her, Mickey Smith and Rajesh Singh from the Daleks (TV: Doomsday). Osgood later unsuccessfully tried to use this strategy to save herself from Missy.
 * Kate Stewart says the Doctor is on UNIT's payroll (TV: Spearhead from Space, The Day of the Doctor), but won't say how much he's being paid (if at all).
 * The Twelfth Doctor appears to have forgotten that he is employed by UNIT, despite the Eleventh making a point of this with Clara (TV: The Day of the Doctor).
 * At some point, St Paul's Cathedral was made bigger on the inside by Missy, who used it to store 91 Cybermen. (TV: Dark Water)
 * The Doctor continues to refer to Danny as "P.E." However, by the end of the episode, he says that he might yet make Maths teacher. (TV: The Caretaker et al) His final use of P.E. to refer to Danny is done with affection after he sees Danny post-conversion.
 * The Doctor gives a reason as to why he doesn't like hugging, something to which he has been against in his current incarnation. (TV: Deep Breath, Listen)
 * The Doctor summons his TARDIS using a TARDIS key. (TV: Father's Day, The Time of the Doctor)
 * Missy tells the Doctor "Nice planet, this. Think I might keep it." She previously told the Half-Face Man she liked the Doctor's new accent and thought she might keep it. (TV: Deep Breath)
 * Missy suggests the Doctor to use the Cybermen army to free the people in the Dalek camps. (TV: The Dalek Invasion of Earth, Destiny of the Daleks, Asylum of the Daleks et.al.)
 * When the Doctor shows up to meet her two weeks late, Clara says he's improving, referring to his appearing three weeks late after being sent for coffee. (TV: Into the Dalek)
 * The Doctor has previously faced other enemies that weaponised the dead, including the Gelth (TV: The Unquiet Dead), the Daleks via nanocloud (TV: Asylum of the Daleks, The Time of the Doctor) and the Hoothi. (PROSE: Love and War)
 * The Cybermen utilise a modified form of rain that can transform organic matter into more of their kind. (COMIC: The Flood)
 * A Cyber-Leader also utilised a virus to turn the dead into Cybermen, but this was a ruse to trap the Sixth Doctor. (AUDIO: The Reaping)
 * While pondering Missy's offer of an army, the Doctor recalls several recent events since beginning his current incarnation:
 * asking Clara if he is indeed a "good man". (TV: Into the Dalek) He later says he is not a good man.
 * being offered a mocking salute by Danny Pink who also called him "Sir" (TV: The Caretaker) He later states that he is not an officer.
 * being told by Rusty that his soul contained hatred (TV: Into the Dalek)
 * telling Robin Hood he himself was not a hero (TV: Robot of Sherwood) He later says this to Missy.
 * also being told by Rusty that he was a "good Dalek" (TV: Into the Dalek).
 * The Doctor and Missy both refer to having been old friends. (TV: The Five Doctors, The Sound of Drums , The End of Time)
 * Missy says she has been up and down the Doctor's timeline and saw all the people who had died to save him. (TV: Deep Breath, Into the Dalek)
 * Missy makes a comment about "Loving the telly [on Earth]". (TV: The Sea Devils, The Sound of Drums)
 * Earth has previously endured a scenario in which people who are supposed to be dead continue to exist in some form. (TV: Miracle Day)
 * Referring to Missy, Clara angrily tells the Doctor "If you've ever let this creature live, then everything that happened today is on you". The Doctor once recalled how many people died because of his mercy. (TV: A Town Called Mercy)
 * Danny's reaction to his upgraded body is similar to the way the "Metaltron" Dalek responded when its biological form was modified against its will- in its case, the way the biomass it absorbed from Rose Tyler had altered its mind to the point it could have feelings. It lamented, "This is not life. This is sickness." Like Danny, it also self-destructed. (TV: Dalek)
 * It is shown in TV: the Magician's Apprentice that Missy survived her apparent death at the hands of the Brigadier. It is later explained in TV: The Witch's Familiar that Missy used the power of the Brigadier's blast to recharge her vortex manipulator and teleport away.

DVD releases

 * Doctor Who: Series 8 Boxset

Blu-ray releases

 * Doctor Who: Series 8 Blu-ray Boxset

Digital releases

 * The episode was released on Google Play, iTunes and Amazon Instant Video in HD or SD, also available as part of the Series 8 digital boxset. The digital boxset contains various features: trailer, interviews, The Ultimate Companion, The Ultimate Time Lord, Inside the World Tour and Doctor Who Extra episodes for each episode.
 * In the US, the series was released through digital streaming services Hulu and Netflix with a subscription.