World Enough and Time (TV story)

, written by Steven Moffat, was the eleventh episode of the tenth series of Doctor Who produced by BBC Wales.

The episode continued the ongoing vault story arc, the Doctor, notably, takes Missy on her first adventure, and entrusts her with his two companions, in his attempt at making her good. The episode also featured Bill being converted into a Cyberman and displayed what appeared to be the beginning of the Twelfth Doctor's regeneration.

It also notably marked the return of John Simm as, seven years after his last appearance in The End of Time. The episode also notably showed John Simm's Master acting alongside Michelle Gomez's, marking the first onscreen appearance of more than one incarnation of the Master, making this episode the first multi-Master story in the show's history.

It even marked the return of the Cybermen in their very first design for the first time in over 50 years since they were first introduced in 1966 and their first formal appearance since Death in Heaven. The episode depicted a fourth alternative account of the genesis of the Mondasian Cybermen - different origins have been shown in the comics The World Shapers and The Cybermen, and the audio story Spare Parts.

Synopsis
The Doctor decides to test how good Missy has become by sending her on a trial run with Bill and Nardole. However, when things go wrong, the Doctor takes over. With Bill trapped in a different time zone, can the Doctor make it to her before it is too late, and who are all those people getting cured?

Plot
The Doctor stumbles from his TARDIS onto a snow-filled landscape, repeatedly chanting no as he falls to his knees. He begins to regenerate.

Sometime prior, while walking through the courtyard at St Luke's University, the Doctor decides to test if Missy can turn good, despite Bill's objections. They discuss it further in St Luke's kitchen, Bill claims even Nardole will resist, but the Doctor assures he won't as he agreed "in his head", Nardole sheepishly agreeing. Their short dispute causes the Doctor to become emotional, due to Missy being the closest thing he has to someone else like him, something that amuses Nardole, who takes a selfie with him to chronicle the moment. Later that day, Bill and the Doctor eat together, the latter convincing her it is a good thing to let Missy try to prove herself as she was once his "man crush". After a brief discussion about the Time Lords and gender stereotypes, Bill confesses that Missy truly scares her. The Doctor tries to promise he can ensure Bill won't die, but admits it can't be guaranteed. Regardless, he assures her that he will be there should things get out of hand.

The plan set, the Doctor drops Missy, Bill and Nardole off on a colony spaceship facing a black hole in the hopes of saving it. Missy introduces herself as 'Doctor Who' to the cameras, which she claims is the Doctor's real name despite the Doctor denying such. He soon becomes impatient with their progress, walking around the TARDIS eating crisps. Missy finally follows suit by deducing why a distress call was made. She also mocks Nardole and Bill's roles as "comic relief" and "exposition" given their genders. They are soon met by a blue skinned humanoid named Jorj who demands to know which one of them is a human. Bill confesses, the Doctor exiting the TARDIS, taking charge as Jorj prepares to shoot Bill as creatures at the bottom of the ship begin to come up in the elevators. Despite the Doctor's pleas, Jorj shoots Bill in the chest, mortally wounding her. Figures with bandaged faces in hospital gowns collect her body, and, using a voice synthesiser, claim that they will fix her but shall not return. The Doctor trusts them, leaving a psychic message for Bill to wait for him when she awakes.

Jorj threatens the Doctor when he attempts to scan the elevators but is threatened by Missy with her umbrella, who states only she is allowed to kill the Doctor and that it will only make the Doctor cross. Once things settle down, the Doctor explains that, due to the lower part of the ship being further away from black hole, time moves faster than the one they are in (the top floor) noting how lifts slowed down when they neared the top due to the difference in gravitational pull, using a red pen in his sonic screwdriver to illustrate. He also states that the creatures on board the ship are the descendants of the crew who went to the lower part of the ship when it got dragged towards a black hole and needed to be reversed, as decades have passed for them even though it has only been two days for Jorj. Jorj admits his confusion; the Doctor mocks him for his lack of knowledge despite supposedly going to "space school", causing the man to reveal he is only a janitor. The Doctor then knocks out Jorj using Venusian aikido so that he and the others can follow Bill. Nardole, stating it has been ten minutes for them, wonders how long Bill has been living below, to which the Doctor replies he hopes they aren't too late.

Meanwhile, at the base of the ship, Bill awakes in a hospital ward with a cybernetic heart fused in to her chest, too shocked to look at it. A feral caretaker looks at her before running off. Coming to her senses, she briefly sees a vision of the Doctor telling her to wait for him only for him to vision. She observes the room, noticing two clocks on the wall, one for floor 1056 (which registers 365030 days) and another for floor 0 (which indicates 2 days).

Bill eventually clambers to her feet and begins to follow the noise of someone chanting "pain", soon finding it be another patient on the ward. She goes to fiddle with its voice synthesise but has to hide as the feral man and a nurse enter the ward, the nurse turning off the synthesiser. The caretaker, revealed to be called Mr. Razor, takes a liking to Bill and brings her to his room. He explains how time passes faster for them compared to the top, using a tin can to illustrate, and offers Bill tea. He explains how Bill was hurt on the upper levels so had to have her heart replaced with a "shiny" cyber heart and that she has been at the hospital for a few months. He also shows her a live feed of the upstairs, which Bill then spends her time watching despite its extremely slow pace. Months go by, Bill witnessing how the Doctor raised his eye brow for a week and braced to explain the situation to his associates. While waiting, Bill recovers enough that she is eventually put to work cleaning the hospital by the nurse while plagued by the Doctor's message to keep waiting.

On one particular day, she contemplates leaving the hospital only for it to alarm the other patients on the ward, unnerving her enough to stay. After being there just over a year, she eventually convinces Razor to take her out of the hospital, where he reveals to her that the patients are being converted in preparation for "Operation Exodus" as the humans' finite lifespan cannot survive the journey back up to the top. They witness how the dying residents are guided to the hospital by the upgraded partially. After a while, Bill's cyber heart fails, forcing them back to the hospital.

More years pass, Bill eventually convincing Razor to take her to the elevators so she can be transferred back upstairs. They sneak in, Razor revealing he has a key to the conversion theatre, wearing a mask in skit attempt to disguise himself. However, once inside, it was revealed to have been a scheme to condemn Bill to a full conversion, as (according to the nurse) people usually scream if alerted to the real reason why they are taken into the theatre. The prototype patients in the room restrain her as the surgeon remarks how the headpiece he will fit on her head will inhibit emotion so she won't care for the pain of the process.

Meanwhile, the Doctor, Missy and Nardole make it to the bottom floor, the Doctor having Missy delve into the ship's computer history to find out what has occurred below, annoying Nardole as that tends to be his job. He and the Doctor explore deeper into the hospital, finding a surgery room. The Doctor uses his sonic to activate the light above the bed, Nardole jumping in surprise at there being partially converted patients in the room. Elsewhere, Razor approaches Missy as she researches, the Time Lady threatening to kill him if he comes closer than three feet.

The others eventually learn of "Operation Exodus", while Missy simultaneously learns the ship came from the planet Mondas, twin planet of Earth. Razor teases her again, drawing a pistol, agitating Missy enough to confront him directly, but he discards the weapon. Razor states that he is "worried about his future" and is surprised Missy can't remember being on the ship beforehand. He talks to Missy about his love of disguises, wondering if she still likes them, revealing "Mr. Razor" was an invention so that Bill did not recognise him as a former prime minister of Britain. He removes his mask, revealing himself as, in his "Harold Saxon" incarnation, now sporting a beard and grey hair. He greets his future self, smiles and says "give us a kiss".

In the surgery room, the Doctor opens a door, revealing a complete Mondasian Cyberman. Backing away, he confirms he means no harm and asks for Bill's location. To his horror, the Cyberman asserts that it is Bill. Missy and her predecessor enter, the latter surprising the Doctor as they profess they have made "the genesis of the Cybermen". Bill begins to cry beneath the mask, as the episode ends.

Cast

 * The Doctor - Peter Capaldi
 * Bill - Pearl Mackie
 * Nardole - Matt Lucas
 * - Michelle Gomez
 * - John Simm
 * Jorj - Oliver Lansley
 * Surgeon - Paul Brightwell
 * Nurse - Alison Lintott
 * Voice of the Cybermen - Nicholas Briggs

Crew
to be added

Locations

 * After being taken by a group of Patients, Bill is moved from Floor 0000 to Floor 1056.
 * Other floors mentioned on the lift scanner are: Floor 1052, Floor 1051, Floor 1050, Floor 1049, Floor 1048, Floor 1047, Floor 1046, Floor 1045, Floor 1044, Floor 1043, Floor 1042, Floor 1041, Floor 1040, Floor 1039, Floor 1038, Floor 1037, Floor 1036, Floor 1035, Floor 1034, Floor 1033, Floor 1032, Floor 1031, Floor 1030, Floor 1029, Floor 1028, Floor 1027, Floor 1026, Floor 1025, Floor 1024, Floor 1023, Floor 1022, Floor 1021, Floor 1020, Floor 1019, Floor 1018, Floor 1017, Floor 1016, Floor 1015, Floor 0951, Floor 0950, Floor 0949, Floor 0948, Floor 0947, Floor 0946, Floor 0945, Floor 0944, Floor 0943, Floor 0942, Floor 0941, Floor 0940, Floor 0939, Floor 0938, Floor 0937, Floor 0936, Floor 0935, Floor 0934, Floor 0933, Floor 0932, Floor 0931, Floor 0930, Floor 0929, Floor 0928, Floor 0927, Floor 0926, Floor 0925, Floor 0924, Floor 0923, Floor 0922, Floor 0921, Floor 0920, Floor 0919, Floor 0918, Floor 0917, Floor 0916, Floor 0915, Floor 0914, Floor 0913, Floor 0912, Floor 0911, Floor 0910, Floor 0909, Floor 0908, Floor 0907, Floor 0906, Floor 0905, Floor 0904, Floor 0903, Floor 0902, Floor 0901, Floor 0900, Floor 0899, Floor 0898, Floor 0897, Floor 0896, Floor 0895, Floor 0894, Floor 0893, Floor 0892, Floor 0891, Floor 0890, Floor 0889, Floor 0888, Floor 0887, Floor 0886, Floor 0885, Floor 0884, Floor 0737, Floor 0736, Floor 0735, Floor 0734, Floor 0733, Floor 0732, Floor 0731, Floor 0730, Floor 0729, Floor 0728, Floor 0727, Floor 0726, Floor 0725, Floor 0724, Floor 0723, Floor 0722, Floor 0721, Floor 0720, Floor 0719, Floor 0718, Floor 0717, Floor 0716, Floor 0715, Floor 0714, Floor 0713, Floor 0712, Floor 1711, Floor 0710, Floor 0709, Floor 0708, Floor 0707, Floor 0706, Floor 0705, Floor 0704, Floor 0703, Floor 0702, Floor 0701, Floor 0700, Floor 0699, Floor 0698, Floor 0697, Floor 0696, Floor 0695, Floor 0694, Floor 0693, Floor 0692, Floor 0691, Floor 0690, Floor 0689, Floor 0688, Floor 0687, Floor 0686, Floor 0685, Floor 0684, Floor 0683, Floor 0682, Floor 0681, Floor 0680, Floor 0679, Floor 0668, Floor 0667, Floor 0666, Floor 0665, Floor 0664, Floor 0663, Floor 0662, Floor 0661, Floor 0660, Floor 0659, Floor 0658, Floor 0657, Floor 0656, Floor 0655, Floor 0654, Floor 0653, Floor 0652, Floor 0651, Floor 0650, Floor 0649, Floor 0648, Floor 0647, Floor 0646, Floor 0645, Floor 0644, Floor 0643, Floor 0493, Floor 0492, Floor 0491, Floor 0490, Floor 0489, Floor 0488, Floor 0487, Floor 0486, Floor 0485, Floor 0484, Floor 0483, Floor 0482, Floor 0481, Floor 0480, Floor 0479, Floor 0478, Floor 0477, Floor 0476, Floor 0475, Floor 0474, Floor 0473, Floor 0472, Floor 0031, Floor 0030, Floor 0029, Floor 0028, Floor 0027, Floor 0010, Floor 0009, Floor 0008 and Floor 0007.
 * Other floors mentioned on the lift level indicator are: Floor 0995, Floor 0994, Floor 0993, Floor 0992, Floor 0991, Floor 0990, Floor 0989, Floor 0988, Floor 0987, Floor 0986, Floor 0985, Floor 0984, Floor 0983, Floor 0982, Floor 0981, Floor 0980, Floor 0979, Floor 0978, Floor 0977, Flood 0976, Floor 0975, Floor 0974, Floor 0973, Floor 0972, Floor 0971, Floor 0970, Floor 0969, Floor 0968, Floor 0967, Floor 0966, Floor 0965, Floor 0964, Floor 0963, Floor 0962, Floor 0961, Floor 0960, Floor 0959, Floor 0958, Floor 0957, Floor 0956, Floor 0955, Floor 0954, Floor 0953, Floor 0952, Floor 0363, Floor 0362, Floor 0361, Floor 0360, Floor 0359, Floor 0358, Floor 0357, Floor 0356, Floor 0355, Floor 0354, Floor 0353, Floor 0352, Floor 0351, Floor 0350, Floor 0349, Floor 0348, Floor 0347, Floor 0048, Floor 0047, Floor 0046, Floor 0045, Floor 0044, Floor 0043, Floor 0027, Floor 0026, Floor 0025, Floor 0024, Floor 0006, Floor 0002 and Floor 0001.
 * Bill is taken to the Conversion Theatre to be fully converted.
 * Razor says that once there was an expedition to Floor 0507, the largest of the solar farms, that didn't survive the trip.

Cybermen

 * The Patients are partially-converted Cybermen.
 * The headpiece is revealed to be the Mondasian Cybermen's emotional inhibitor.
 * The Patients use speech synthesizer computers to talk.
 * The Cybermen are part of a neural net.

Science

 * The ship is reversing away from the gravitational pull of a black hole.
 * Due to time dilation, time is slower on one side of the ship than on the other.
 * Basically the closer one is to the gravity source, the slower time will pass.
 * The Doctor calls it Superman-gravity.

Biology

 * The Doctor calls the heart the "most important [human] organ".
 * The Doctor complains that humans only have one heart.
 * The Doctor says he has hidden arms.

Technology

 * The sonic screwdriver can be used as a marker pen.
 * The ship is fitted with inertia lifts.
 * The ship is 400 miles long and a hundred miles wide.
 * The ship has CCTV cameras.
 * Missy, Nardole and Bill wear earpieces to communicate with the Doctor inside the TARDIS.
 * The ship's thrusters are on reverse.
 * Razor says that on most people, the Cyber heart looks like a vending machine.
 * The surgeon uses a machine called Medi-Ject 08 to operate on the Patients.

TARDIS

 * The individual panels on the console can be taken off and moved around the entire control room, having a long cable connected to it.

Species

 * It's offensive to mistake Time Lords for humans. At least according to Missy.

People

 * The Twelfth Doctor is shown regenerating (in the pre-titles sequence, an event that is yet to come).
 * In his first incarnation, the Doctor had a crush on the Master, while at the Academy.
 * Missy comes up with other words to describe her companions, including "assistants", "pets", "snacks" and "disposables".
 * Nardole was once blue.
 * Missy thinks "fear" is the emotion called spanking.
 * Jorj is the colony ship janitor.

Nicknames and aliases

 * Missy uses the alias "Doctor Who" and gives Bill and Nardole the nicknames "Thing One" and "the Other One" respectively.
 * Missy says that the Doctor's real name is Doctor Who.
 * Missy calls Bill "exposition" and Nardole "comic relief", referring to two types of stock characters typically found in story writing. She calls them their genders.
 * Missy calls Jorj her stallion.
 * Missy calls Jorj "Smurf".

Culture

 * Missy briefly dabs.
 * According to the Doctor, Time Lords don't have fixation on gender and gender roles that humans do.
 * Nardole takes a selfie with the Doctor.
 * The creation of the Cybermen is called "Operation Exodus".

Foods and beverages

 * The Doctor eats a packet of crisps labelled Bamon crisps.
 * Attempting to mimic human flirting, Missy says to Jorj "if I'm in the shower, just bring me some beans on toast".
 * Bill puts chipped potatoes in a fryer.
 * Peppers and cabbages are seen in the University kitchen.
 * The Doctor and Bill eat chips.
 * Bill eats a bacon sandwich. The Doctor tells her to "go and tell a pig about [her] moral high ground.
 * Nardole eats a Jaffa Cake.
 * "Razor" makes tea for Bill.
 * "Razor" uses a can of baked beans to illustrate the ship.
 * "Razor" is cooking bacon.
 * Missy suggests to make a soup out of "Razor"'s vital organs.

Music

 * Opera music cab be heard from Conversion Theatre.

Story notes

 * The read-through for World Enough and Time took place on 21 February 2017, and filming took place between 24 February and 28 March.
 * This episode marks the first on-screen appearance of the original design of the Mondasian Cybermen since the First Doctor television story, The Tenth Planet in 1966.
 * This episode marks the return of John Simm's, who last appeared in The End of Time in 2010.
 * This episode marks the first time that more than one incarnation of the Master has appeared on-screen.
 * One of the solar farms look like the outside areas on Gliese 581 D from TV: Smile.
 * The Master's line comparing the scenario to being more like a "Genesis of the Cybermen" is a reference to the 1975 Doctor Who story TV: Genesis of the Daleks, which showed the Fourth Doctor being sent to the creation of the Daleks. Following the success of Genesis of the Daleks, a story entitled Genesis of the Cybermen was planned, but never produced.
 * For the first time in the show's history, the Doctor actually self-identifies using the name "Doctor Who". However, it does seem like a bit of an in-joke. He has previously been referred to as such: in The War Machines, WOTAN says "Doctor Who is required" (due to a script mistake); in The Highlanders, the Second Doctor introduces himself as "Doktor von Wer" (German for "Doctor [of] Who"); in The Underwater Menace, the Second Doctor signs a note with "Dr. W."; in The Dæmons, the Third Doctor introduces himself as "the great wizard Qui Quae Quod" (Latin variations of "Who"); from Doctor Who and the Silurians to The Five Doctors and in What He Wants..., the Doctor's car Bessie's plate read WHO 1, in Battlefield it read WHO 7, and in The Dying Days it read WHO 8; in The Kingmaker, the Fourth Doctor wrote a series of children's books accidentally published as Doctor Who Discovers; in Rose, a website called whoisdoctorwho.co.uk asks "Who is Doctor Who?"; and in Fogbound, the Master addresses a postcard to the Third Doctor as "Dr. Who". Although Missy claims that "Doctor Who" is the Doctor's real name, she also explicitly says she calls herself Doctor Who to head off the usual response heard when the Doctor introduces himself and people reply, "Doctor who?"
 * "Operation Exodus" was a continual concern for the inhabitants of Moonbase Alpha in the 1970s TV series Space: 1999. There, it was an evacuation plan for an orderly transfer of the Moon's inhabitants to another location--originally back to Earth, but eventually adapted to any habitable body.
 * The episode is one of few instances of the use of profanity, with Missy saying the word "bitch".
 * When the Master unmasks himself, an alarm bell in the background sounds in time with a drumbeat. The drumbeat is also heard when he enters the operating theater alongside Missy. The Master has had an association with drums before in TV: Utopia, The Sound of Drums, Last of the Time Lords and The End of Time.

Ratings

 * 3.37m (UK Overnight figures)

Filming locations

 * Scenes outside the hospital were shot in Cardiff Bay.

Production errors
to be added

Continuity

 * Missy again wears a hat and is carrying an umbrella. (TV: Deep Breath et al.)
 * Missy dances to the alarm sound. She previously danced to the continued "EXTERMINATE" chant from the Supreme Dalek. (TV: The Witch's Familiar)
 * The Doctor notes Missy's use of the TARDIS to retrieve him along with Bill and Nardole from Mars. (TV: Empress of Mars)
 * Blue-skinned humanoids are seen again. (TV: The End of the World, The Pandorica Opens, Oxygen)
 * Bill is working in the kitchen at St Luke's University. (TV: The Pilot)
 * The Doctor again complains about humans only having one heart. (TV: The Shakespeare Code, The Power of Three)
 * The Doctor has previously left a message in a companion's subconscious. (TV: The Pandorica Opens/The Big Bang)
 * The Doctor has previously arrived at a location where the "skeleton crew" had had disappeared. (TV: Smile)
 * The original Mondasian Cybermen appear again, and Mondas is shown on a screen. Missy notes that it's a twin to Earth. (TV: The Tenth Planet)
 * In his fifth incarnation, the Doctor saw the Mondasians who remained on Mondas convert themselves into Cybermen for a similar reason. (AUDIO: Spare Parts)
 * This is at least the fourth time the Doctor has witnessed the "genesis" of some form of Cybermen. (AUDIO: Spare Parts, COMIC: The World Shapers, TV: Rise of the Cybermen / The Age of Steel)
 * Nardole screams due to being surprised. (TV: Extremis)
 * Missy previously encountered the "Harold Saxon" Master. (COMIC: The Abominable Showmen / The Five Masters)
 * The Doctor has been on another space colony that orbited a black hole. (TV: The Impossible Planet / The Satan Pit)
 * The Doctor has to travel to a different time zone of the same location to rescue his companion, who waits for him, but he arrives too late. (TV: The Girl Who Waited)
 * The topic of the Doctor's "real name" is discussed. (TV: The Name of the Doctor) The Doctor again states how he actually likes being asked "Doctor Who". (TV: The Bells of Saint John) Missy also claims to know the Doctor's real name; previously, River Song possessed this knowledge (TV: Forest of the Dead, et al.) and Clara Oswald briefly did so before a time reset. (TV: Journey to the Centre of the TARDIS)
 * The Doctor is shown regenerating. (TV: The Tenth Planet et. al)
 * The Doctor says going on an adventure is something he and Bill do on Saturdays, just as Wednesday used to be his day for adventures with Clara Oswald. (TV: The Bells of Saint John, et al.)
 * The Doctor has previously said he like Saturdays. (TV: The Stolen Earth)
 * The Doctor refers to him and the Master meeting at the Time Lord Academy. (PROSE: Divided Loyalties, TV: The Sound of Drums, Terror of the Autons)
 * The Doctor and Missy each mention how they met at the Academy on Gallifrey and how they chose their names that day, among other promises. (TV: The Sound of Drums, The End of Time)
 * The Doctor mentions the Master's desire to destroy the universe rather than explore it, as they had initially promised. (TV: Last of the Time Lords, The End of Time)
 * The Doctor tries to remember if he ever had a female incarnation. All incarnations of the Doctor up to and including the Twelfth, all male, came together to save Gallifrey in a pocket universe. (TV: The Day of the Doctor) During a mind battle with Morbius, further incarnations were shown, seemingly having been hidden. (TV: The Brain of Morbius)
 * Bill remarks on how Gallifreyans differentiate gender by calling themselves "Time Lords" and "Ladies". (TV: Dark Water)
 * The Cybermen are shown to be able to cry and feel pain. (TV: Doomsday, Rise of the Cybermen)
 * Bill calls the Doctor an idiot, mirroring how Nardole did likewise. (TV: Extremis)
 * The Doctor knocks out Jorj using Venusian aikido. The fighting style was prominently used by his third incarnation. (TV: Inferno, Colony in Space, The Mutants, The Green Death, The Time Warrior, COMIC: The Celluloid Midas)
 * The surgeon explains that the headpiece of the cyber-suit acts as an emotional inhibitor so Bill won't care about the pain. (TV: The Age of Steel)
 * Once again, the Doctor witnesses a companion suffer a mortal injury, (TV: Face the Raven, Forest of the Dead) only for technology to be used to arrange for them to stay alive; in all cases, their hearts no longer function. (TV: Hell Bent, The Name of the Doctor)
 * Other associates of the Doctor have previously been converted into Cybermen, such as Jackie Tyler (TV: Rise of the Cybermen), Yvonne Hartman (TV: Doomsday), and Danny Pink (TV: Death in Heaven). It similarly occurred when Oswin Oswald was converted into a Dalek. (TV: Asylum of the Daleks)
 * The Master has allied with Cybermen before. (TV: The Five Doctors, Dark Water / Death in Heaven, PROSE: Birth of a Renegade)
 * The Master adopted the guise of "Razor" so Bill would not recognise him from his time as Prime Minister of the United Kingdom. (TV: The Sound of Drums / The Last of the Time Lords)
 * The Master is sporting a beard, similar in style to his previous incarnations. (TV: Terror of the Autons - Frontier in Space, The Keeper of Traken-Survival) He also mentions and displays a love of disguises, as, again, in past incarnations. (TV: Time-Flight, et al.)
 * Missy not remembering being on the ship in her previous incarnation echoes how the Eleventh Doctor didn't remember meeting his other selves until "time caught up". (TV: The Day of the Doctor) Back then, the War and Tenth Doctors, along with all other incarnations involved, did not retain memories of saving Gallifrey until the Eleventh Doctor went through that adventure himself.
 * Missy comedically remarks on the age gap between the Doctor and his companions. The Dream Lord made a similar remark. (TV: Amy's Choice)
 * Razor says the residents of floor 1056 must upgrade, typical of Cybermen. (TV: Rise of the Cybermen, Age of Steel, Nightmare in Silver)
 * The Doctor criticises Bill for eating a bacon sandwich when arguing about Missy's morality. This echoes an earlier conservation between the two. “Hardly anything’s evil. Most things are hungry. Hungry can look a lot like evil from the wrong end of the cutlery. Do you think your bacon sandwich loves you back?” (TV: The Pilot)

DVD releases
to be added

Blu-ray releases
to be added

Digital releases
to be added