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World Enough and Time was the eleventh episode of series 10 of Doctor Who.

The episode continued the ongoing story arc concerning Missy's rehabilitation, with the Doctor taking Missy on her first adventure and entrusting her with his two companions in an experiment to test how good she has become. It also showed Bill Potts being converted into a Cyberman and displayed what appeared to be the beginning of the Twelfth Doctor's regeneration, setting the stage for the end of the Twelfth Doctor's tenure.

World Enough and Time notably featured the return of John Simm as the Saxon Master, seven years after his last appearance in The End of Time, marking the first time a previous actor of the Master had returned to the television series after being recast. The episode also showed John Simm's Master acting alongside Michelle Gomez's Missy, marking the first onscreen appearance of more than one incarnation of the Master.

It also marked the return of the Mondasian Cybermen on television for the first time since they were introduced in 1966's The Tenth Planet, and the Cybermen's first significant appearance since series 8's 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. This was, however, explained in The Doctor Falls with a reference to "parallel evolution".

In 2023, despite World Enough and Time together with The Doctor Falls ranking as the most popular Twelfth Doctor TV story ahead of Heaven Sent in a poll by Doctor Who Magazine,[1][nb 1], a later DWM poll that year with a shortlist of 37 finalists including the two aforementioned stories declared World Enough and Time/The Doctor Falls the second most popular TV story of the first 60 years of Doctor Who, behind the winner, Heaven Sent.[2]


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?


The Twelfth Doctor starts to regenerate

The Doctor regenerating.

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, where 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 on the University roof, and the Doctor convinces Bill to let Missy try to prove herself. 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 that she is human, and the Doctor exits 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 voice synthesisers, 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.

Bridge on Floor 0000 on Mondasian colony ship

The TARDIS lands on a colony ship.

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 the black hole, time moves faster on the bottom floors than it does on the top floor that they are in. He notes 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 into her chest. 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 vanish. She observes the room, noticing two clocks on the wall, one for Floor 1056 - which registers 365034 days, 23 minutes, and 26 seconds, or 999.430015 years - and another for Floor 0000, which indicates 2 days, 10 hours, 45 minutes, and 17 seconds.

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 synthesiser but has to hide as the feral man and a nurse enter the ward; the nurse mutes 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 those on the top floor, 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 eyebrow 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.

Line of patients (WEAT)

The patients on Floor 1056.

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 partially upgraded. 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 is revealed to have been a scheme to condemn Bill to a full conversion as, according to the surgeon, 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 about 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, asking her if she doesn't remember being on the ship before; the Time Lady threatening to kill him if he comes closer than three feet.

Cyber-converted Bill

Twelfth Doctor discovers he is too late to save Bill.

The others eventually learn of Operation Exodus, while Missy simultaneously learns the ship's origin: Mondas, twin planet of Earth. Razor teases her again, drawing a pistol, taunting Missy that the Doctor will never forgive her or set her free after he discovers what she did to Bill; Missy insists that she hasn't done anything to Bill, but Razor tells her that she did a long time ago. By now, Missy is agitated enough by Razor to confront him directly, threatening to extract his vital organs and make soup out of them. Razor declares that she would never be so self-destructive before dropping his gun, stating that neither would he. Razor talks to Missy about his love of disguises, wondering if she still likes them; "Of course," he continues, "they are rather necessary when you happen to be... someone's former Prime Minister". He removes his mask, revealing himself as the Saxon Master to Missy's shock, now sporting a beard and grey hair. He greets his future self, smiles and remarks that he is very worried about his future before saying "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". Nardole runs away in fear, as the Doctor looks on in horror; his trial to test Missy's goodness has just been turned upside down in more ways than one. Not only has Missy reverted to her cruel self, the old Master is here too. Bill reaches towards the Doctor and, in the Mondasian Cyberman's stilted, sing-song voice states "I waited. I waited for you..." as she begins to cry beneath the mask.



more to be added

General production staff

Script department

Camera and lighting department

Art department

Costume department

Make-up and prosthetics

General post-production staff

Special and visual effects


Not every person who worked on this adventure was credited. The absence of a credit for a position doesn't necessarily mean the job wasn't required. The information above is based solely on observations of the actual end credits of the episodes as broadcast, and does not relay information from IMDB or other sources.






  • The Doctor calls the heart the "most important [human] organ", and notes that humans only have one.
  • The Doctor says he has hidden arms.




  • According to Missy, it is offensive to mistake Time Lords for humans.


Nicknames and aliases[]

  • Missy uses the alias "Doctor Who" and gives Bill and Nardole the nicknames "Thing One" and "the Other One" respectively. Missy claims that the Doctor's real name is "Doctor Who", and that he chose it himself.
  • 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. Later, she mockingly calls him "Smurf".


  • Missy briefly dabs.
  • According to the Doctor, Time Lords do not have the fixation on gender and gender roles that humans do. Bill remarks that the Doctor's species call themselves "Time Lords", to which the Doctor responds "yeah shut up".
  • Nardole takes a selfie with the Doctor.
  • The creation of the Cybermen on Floor 1056 is codenamed "Operation Exodus".
  • Missy refers to Bill and Nardole as "Thing One and Thing Two", in reference to The Cat in the Hat.

Foods and beverages[]


  • Shortly after fully waking on Floor 1056, Bill hears opera music playing from the Conversion Theatre whilst work occurs in there.


  • The title was drawn from the opening line of Andrew Marvell's To His Coy Mistress, published posthumously in 1681. The poem represented an entreaty for a woman to respond favourably to the speaker's romantic advances, contrasting the lengths to which he would go if he were unencumbered by time and space, with the urgency imposed by the true brevity of the human lifespan.
  • "Operation Exodus" was a continual concern for the inhabitants of Moonbase Alpha in 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.

Story notes[]


Brian Minchin Talks World Enough And Time - The Aftershow - Doctor Who The Fan Show

This episode's Aftershow on Doctor Who: The Fan Show.

  • This marks the first appearance of the original design of the Mondasian Cybermen in a televised story since the Cybermen's debut story, The Tenth Planet in 1966.
  • This episode also marks the return of John Simm's Master, who last appeared in The End of Time in 2010. It also marks the first time that more than one incarnation of the Master has appeared on-screen together.
  • The Master's line comparing Operation Exodus to being more like a "Genesis of the Cybermen" is a reference to 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 (although this is just one of many later stories to take up the concept, a full list of which can be found at Genesis of the Cybermen). It is also a play on Operation Exodus and the biblical books of Exodus and Genesis. Perhaps coincidentally, Doctor Who Magazine had previously published a trilogy of stories entitled Exodus/Revelation!/Genesis!, which also featured the Cybermen. Also, Genesis and Revelation (but not Exodus) have been used as titles in the '...of the Daleks' formula.
  • For the first time in the television series (but far from without precedent across the franchise), the Doctor actually self-identifies using the name "Doctor Who". He has previously been referred to as such in the TV series (examples from across the franchise being far too numerous to list): 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 is introduced as "the great wizard Qui Quae Quod" (Latin variations of "Who"); from Doctor Who and the Silurians to The Five Doctors, the Doctor's car Bessie's plate read WHO 1, and in Battlefield it read WHO 7, and in Rose, a website called Doctor Who? asks "Who is Doctor 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?". She also states that he chose the name himself, suggesting she means "real name" in the sense of self-designation.
  • 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 theatre alongside Missy. The Master has had an association with drums before in Utopia, The Sound of Drums, Last of the Time Lords and The End of Time.
  • This episode, along with its following part, was ranked as Doctor Who Magazine readers' favourite Twelfth Doctor story in their 60th anniversary poll of 2023.[1] The same set of polls, however, ranked the two-parter the readers' second favourite in a list of 37 finalists.[2]
  • As far back as 2009, John Simm had assured Steven Moffat of his openness to return as the Master. Indeed, Simm was hoping to be involved in The Day of the Doctor. Moffat was keen to have an actor of Simm's calibre back, but, having introduced Missy, he knew he would have to delay Simm's appearance to avoid undermining the new incarnation. As such, the finale presented an ideal opportunity to bring the two Masters together, a plot twist that had never previously been exploited on television.
  • For the story's setting, Steven Moffat conceived of a colony ship where the passengers became trapped for generations following the malfunction of the robotic pilot. This notion was refined through conversations with his son, Joshua, who was studying Physics at university. The younger Moffat had developed an interest in relativistic effects: the way that normal physical laws broke down at speeds approaching that of light, or in the presence of an enormous mass. One associated phenomenon was time dilation, which saw time passing at different rates for different observers, and he noted his surprise that it featured so rarely in popular science-fiction. This discussion prompted Moffat to replace the ship's robotic pilot with a black hole, which would cause time to accelerate on the parts of the vessel that were closest to it. This device would also provide the opportunity to incorporate more recent types of Cybermen.
  • The eerie institution in which Bill found herself after awakening on Floor 1056 was inspired by Steven Moffat visiting his mother in hospital.
  • Jorj was briefly the more prosaic George.
  • The proto-Cybermen carrying drip feeds were originally dubbed Top Knots, in reference to their balaclava-like head coverings, although they would later simply be known as Patients.
  • Initially, the closing zoom on Bill's eye was to reveal the appearance of a star-like defect, the same abnormality that Heather had possessed in The Pilot.
  • This two-parter formed Block Seven of season ten.
  • John Simm decided that he would portray a distinctly older version of his Master, in part because his hair had gone grey in the interim. He also opted to grow a goatee, in homage to Roger Delgado and Anthony Ainley; Simm had previously considered sporting similar facial hair for his initial appearances as the Master, before he and Russell T Davies had decided that it was unnecessary.
  • For the Doctor's use of Venusian aikido, Peter Capaldi studied footage of Jon Pertwee in an attempt to recreate the Third Doctor's movements when applying the extraterrestrial martial art.
  • John Simm's return as the Master was meant to be a surprise, but the BBC announced it ahead of time in order to avoid press leaks. Simm was deeply unhappy with this, as he felt that most viewers were able to see through his disguise. Steven Moffat was also displeased at this.


  • 3.37 million (UK Overnight figures)
  • 5.01 million (UK final)[3]

Filming locations[]

Production errors[]

If you'd like to talk about narrative problems with this story — like plot holes and things that seem to contradict other stories — please go to this episode's discontinuity discussion.

to be added


Home video releases[]

DVD & Blu-ray releases[]

  • This episode was included in the Series 10, Part Two DVD and Blu-ray boxsets in region 1/A on 12 September 2017, in region 2/B on 24 July 2017 and in region 4/B on 16 August 2017.
  • This episode was also released as part of the Complete Tenth Series DVD and Blu-ray boxsets in region 1/A on 7 November 2017, in region 2/B on 13 November 2017 and in region 4/B on 29 November 2017.

Digital releases[]

  • In the United Kingdom, this story is available on BBC iPlayer.

External links[]



  1. Polls by DWM are statistically invalid, as they do not feature a random sample of people. Respondents choose to participate on their own initiative, and are made aware of the poll because they subscribe to or at least frequently buy DWM. Thus, the poll is clearly weighted towards Doctor Who fans who are also residents of the United Kingdom. The views reflected almost certainly do not represent the "casual" viewer of Doctor Who, non-English speaking fans, or other groups of fans who simply don't read or have access to DWM.


  1. 1.0 1.1 DWM 594[which?]
  2. 2.0 2.1 DWM 597 - Magnificent Heaven, Page 26
  3. Ratings DW