The Timeless Children (TV story)

The Timeless Children was the tenth and final episode of series 12 of Doctor Who.

The episode brought to light an account of the Doctor's origins in which, prior to becoming the First Doctor, they had lived many forgotten lives as the Timeless Child. This new thread in the ongoing tapestry brings the Doctor, once again, to the forefront of Time Lord history.

In this new account, the Timeless Child was discovered near a boundary to another dimension or reality by the Shobogan traveller Tecteun, who took her in as her own. Their regenerative abilities were attentively studied by Tecteun and eventually replicated. This is put forward as the true origin of regeneration on Gallifrey. A radical result of this retroactive continuity is that the Doctor, in their earliest lives, was the biological template upon which Time Lord society was founded.

It also offers a new explanation for pre-Hartnell incarnations like the so-called "Morbius" Doctors, and continues to push the mystery around the "Fugitive" Doctor played by Jo Martin.

The Timeless Children also brought another redesign of the Cybermen not long after the warrior-class Cybermen in Ascension of the Cybermen in the form of CyberMasters - a branch created by the Master with the ability to regenerate.

The episode also brought about another shift in the current status quo, with the Doctor's companions, Ryan, Graham, and Yaz being returned to the 21st century without the Doctor, for their protection, with the group still being separated by the end of the episode.

Synopsis
Gallifrey is dead, the Master is in control of an army of Cybermen ready to take over the universe, and Graham, Ryan, and Yaz are trapped, being hunted down with the last remnants of humanity. But for the Doctor, one question remains... Who is the Timeless Child?

Plot
Immediately following the previous episode, forces the Doctor to join him on Gallifrey through the Boundary or else he will use his Tissue Compression Eliminator on Ryan, Ethan, and Ko Sharmus. Pulling her through, the others intend to follow, but a Cybercarrier appears overhead.

Inside, Graham, Yaz, Ravio, Yedlarmi, and Bescot attempt to sprint from Ashad and his Cybermen. Bescot holds them off as the others scramble through a vent, but she is killed in the process.

The Doctor and the Master land outside the ruins of Gallifrey's Capitol and he taunts her for his work. He plans on showing her a tour of the ruined Citadel and reminds her there is nothing she can do to help her friends.

On the Cybercarrier, the group makes it to a storage vault as Graham comes up with a mad idea. Reaching another carrier full of disabled Cyber-Warriors, he plans to hide in their armour as a disguise. Knowing how nasty the insides of a cyber-suit may be, Ravio works to disconnect the suits from their shared neural network as the others work on the bodies inside. Meanwhile, Ko Sharmus shows Ryan and Ethan his very limited weapon store. Although Ryan has gained an aversion to weapons since travelling with the Doctor, the others say he has no choice.

The Master leads the Doctor to the centre of the Citadel, reminding her of all the times they spent there, now all in ruins. As he talks, a mini scanner in his pocket notifies him that the Cybermen have reached the Boundary. He extends a holographic call to Ashad and they introduce themselves. The Master coaxes him to join him on Gallifrey and successfully convinces them to send some Cybermen to Ko Sharmus' planet as the carrier sets course for Gallifrey. As dozens of Cybermen land in front of the humans, they prepare for battle.

Meanwhile, Graham and Yaz take a moment to relax while Ravio and Yedlarmi work on the cyber-suits. He lets her know in case they do not survive that he thinks she is incredibly impressive, arguably more so than the Doctor, as she keeps fighting without Time Lord technology to help her. He says that she is doing the human race proud, leaving her deeply moved. With a tear in her eye, she jokes that he is not bad either, just as the others say their plan is ready. Meanwhile, the Cyberguards alert Ashad to the humans' meddling. Ashad plans to get them himself.

On Gallifrey, the Doctor tries to question the Master on why he would work with the Cybermen, but he prepares to show her the unbelievable truth that he mentioned. Knowing she will not believe him, he takes her to the Matrix, the total of all Time Lord knowledge that he chose not to destroy. He explains he was casually hacking the system when he found the truth for himself. Capturing the Doctor in a paralysis field, she appeals to him to save her friends but he ignores her. Preparing to send her deep into the Matrix, he warns her that it will hurt.

Ashad enters the Cybercarrier's storage unit where the four humans have hidden in cyber-suits. After a lot of deep analysis of them, he decides nothing is wrong and is called away by one of his guards as they are reaching the Boundary. Graham tries to find a way out for the group.

In the Matrix, the Master shows a pained Doctor the secret history of Gallifrey, with both of them appearing in the projections of his story. He reveals that the Shobogans, not the Time Lords, were the indigenous species on the planet. One of them, named Tecteun, was the planet's first space explorer and one day, upon searching another planet, she found a gateway to another dimension or universe. Beneath it lay a young girl. Tecteun adopted her and after she grew up a little, she brought the child back to Gallifrey to figure out where she came from, but with no luck. Then, one day, when playing on a cliffside with a friend, the child fell off. However, instead of dying, she regenerated - the first time this ever happened on Gallifrey.

The Master is briefly interrupted from telling his story by the arrival of the Cybercarrier over the Capitol. Near the Boundary, the Cybermen land to take down the humans, but they are distracted by Ko Sharmus' weaponry which they quickly destroy. It falls to Ryan to throw a bomb at a large group of them and he succeeds, overcoming his nervousness due to his dyspraxia. However, one is left standing and he runs.

Ashad finally arrives in the Citadel and the Master says he wants to help him. However, Ashad reveals his plan is to wipe out all organic life in the universe via the death particle, placed in his chest by the Cyberium. Ashad explains that his warriors will be fully automated, including himself, but the Master is disappointed in the lack of imagination of simply making themselves robots. Although Ashad is offended, he allows the Master to use his cyber-conversion processes. The Master follows him as his consciousness deals with the Doctor.

The Master's story continues. With the child having regenerated, Tecteun dedicated her life to solving that mystery, through several of the child's forced regenerations as they grew older. Finally, after many years, she cracked the code. Taking a risk to test it on herself, the regeneration eventually worked, turning her male. With the knowledge gained, Shobogans created the Citadel, discovered time travel, and Tecteun, as part of the ruling elite, chose to have the ability grafted into his species, transforming them into Time Lords. They chose to limit their regenerations to twelve, with the "Timeless Child" as the base of Gallifreyan genetics, "and the rest, as they say, is history." With the story all but finished, the Doctor asks what happened to the child. The Master laughs, calling it obvious, and reveals that the child is, and always was, the Doctor herself. She cannot contain the revelation as the Matrix starts to warp around her.

Meanwhile, Ryan, Ethan, and Ko Sharmus run from the Cybermen, grab what few guns they have and try to take a few down. Although a few are killed, one captures Ethan and gives the others ten seconds to surrender before he is executed. As the two arrive to surrender, the Cybermen's weapons fire, but they arrive to find four Cybermen stood over some collapsed ones. One takes its helmet off, revealing Yaz inside, and the rest of her group appear as well.

Ashad leads the Master to the Cybermen's storage inside the carrier, but he says that his orders will be given by the Cyberium. He tells the Master that it will not vacate him while he lives, so the Master calmly tissue compresses him, killing him instantly. The Cyberium appears in mid-air, the Master admitting he thought he would be killed by the death particle. Keeping the miniaturised Ashad and his death particle close, the Master proposes to be the Cyberium's "business partner" and it enters his body with the promise of absolute supremacy.

In the Matrix, the Doctor wakes up in a projection of a vast green landscape with the Master. She refuses to believe his story, knowing her history, but he promises it is true. The Master explains her real childhood did happen, it just was not the start of her life. He is most furious, however, that her genetics went into the creation of him. Shoving the Master to the ground, she demands he shows her the rest. Tecteun and the child were inducted into a clandestine organisation called the Division, led by a Time Lord called Solpado, whose job it was to intervene in time when necessary, with the child's memories being erased of their time working for them. However, the scene shifts to that of Brendan from Ireland, which the Doctor admits to having seen visions of. It is revealed his retirement clock reads "For Services To The Division" before the scene disappears. The Master explains the details of the child, and the Doctor's, life were redacted from the Matrix, unrecoverable, but it took up a lot of space. Tecteun masked the story to be that of the fictional Brendan so it would appear unremarkable. The Master wonders how many more lives the Doctor has had.

The Doctor wakes up in the Citadel as the Master explains that, although he ruined the planet, he kept the Time Lords' bodies just in case. Experimenting, the Master decided to create a race of Cybermen made out of Time Lords, with the ability to regenerate, and his new CyberMasters, with which he will use to take over the universe, come to greet him. To test his theory, he orders one to shoot another and it collapses to the ground, dead. However, after a few seconds, it regenerates and returns to its rank. With the Doctor still paralysed, the Master leads off his new army.

Back by the Boundary, the Doctor's friends reunited gather to visit Gallifrey. Of the seven of them, Yaz volunteers to try crossing first and the group successfully lands on the alien planet. Yaz swears that they will find the Doctor and save her as she saved them.

In the Matrix, the Doctor wakes up to find a vision of the "Fugitive" Doctor, who is equally confused as to how she is there. The Thirteenth Doctor asks if her memories of being her were erased before she was reverted to a child and had the regeneration limit applied, but the Fugitive Doctor does not have the answers. However, she states that the Thirteenth Doctor has never been limited by her past before and should not be again, but she still does not know how to stop the Master. The Fugitive Doctor tells her to focus on "the one thing he said that you didn't understand" and suggests she should blow the Matrix's mind. She vanishes and the Doctor decides to overload the Matrix with all of her memories from her past regenerations. Finding her energy back, she focuses intently and her entire history of faces, friends, and enemies in reverse chronological order flashes before her, going further past the First Doctor to the Fugitive Doctor, the so-called "Morbius" Doctors, and finally the Timeless Child before the Matrix explodes.

The Doctor collapses on the floor of the destroyed Citadel, freed but unconscious, as her friends' group finds her. She comes to and they share their new findings, deciding to destroy the Cybercarrier, though the Doctor admits it will not stop the Master. However, the Doctor remembers the one thing she did not understand - Ashad claiming he held the death of everything - and the others tell her the story of the death particle. With a plan to detonate it on Gallifrey then escape, the Doctor locks on to the Master's location.

Around the Cybercarrier, her allies set up bombs but cannot find the Master. However, the Doctor discovers Ashad's miniaturised body. The Master makes psychic contact with the Doctor, having laid her a false trail, but she tells them that they will meet in the Matrix Chamber alone. As Ko Sharmus' bombs detonate early, the group, split in two, leaves as fast as possible as the Cybercarrier blows up.

Escaping to the Capitol and finding a room of default and unused TARDISes, she programs one to take her friends, and the refugees, back to the 21st century. Ko Sharmus has one hand-detonated bomb left and the Doctor plans to use it on the death particle, destroying all remaining life on Gallifrey, including the Master and Time Lords. Knowing she will die too, the Doctor bids one final heartbroken farewell, telling her "fam" to "live great lives."

In the Matrix room, the Doctor meets the Master, with his CyberMasters still in tow. He tells her that he will let her live to witness his victories and that the Cyberium lives in him now, believing to have broken the Doctor. However, she tells him she feels the opposite: that she is so much more than she previously imagined. Instead, she pulls out the miniaturised body of Ashad attached to the explosive. Despite being goaded by the Master to detonate it and become like him, she is unable to. However, Ko Sharmus appears having left the TARDIS, explaining how he sent the Cyberium back through time and space and offers to take the death particle as penance for failing to suitably hide it. As the Doctor sprints away, she escapes in another TARDIS as Ko Sharmus triggers the death particle, the explosion consuming Gallifrey and everything on it.

The Doctor's allies arrive on contemporary Earth in their TARDIS, which materialises as a detached house to blend in with the housing estate where it has landed, with them unaware of the Doctor's fate. The Doctor lands the other TARDIS, in the shape of a tree, in a quarry on the refugees' planet near her own and she fondly greets it. She takes a moment to herself, extremely shaken by the events, before going to pick up her friends. However, as she prepares to take off, a siren sounds and three Judoon beam in. The Judoon Captain introduces the trio as a cold case unit, who have tracked down the long-lost escaped fugitive, the Doctor. The Doctor is arrested and is sentenced to life imprisonment in a maximum-security facility. Being teleported to a solitary prison located inside an asteroid in deep space, she can only stammer "what?!" as she looks out on her surroundings, completely isolated, with no way out, and very far from home.

Cast

 * The Doctor - Jodie Whittaker
 * Graham O'Brien - Bradley Walsh
 * Yasmin Khan - Mandip Gill
 * Ryan Sinclair - Tosin Cole
 * - Sacha Dhawan
 * Ashad - Patrick O'Kane
 * Ko Sharmus - Ian McElhinney
 * Ravio - Julie Graham
 * Yedlarmi - Alex Austin
 * Ethan - Matt Carver
 * Bescot - Rhiannon Clements
 * Tecteun - Seylan Baxter
 * Solpado - Kirsty Besterman
 * Judoon Captain - Paul Kasey
 * Voice of Cybermen & Judoon Captain - Nicholas Briggs
 * Cybermen - Matthew Rohman, Simon Carew, Jon Davey, Richard Highgate, Richard Price, Mickey Lewis, Matthew Doman, Paul Bailey
 * Special guest appearance by


 * The Doctor - Jo Martin

Uncredited cast

 * The Timeless Child - TBA, TBA, Grace Nettle, Leo Tang , TBA, TBA, Jesse Deyi
 * Omega - Mark Corden

Crew
More to be added

Species

 * Shobogans were the original indigenous species of Gallifrey, some of whom genetically altered themselves into the Time Lords through Tecteun's research on the Timeless Child.
 * The Timeless Child's species are a species from another reality or dimension that have the ability to regenerate infinitely and continuously change their appearance. Tecteun was able to splice elements of their DNA into herself and other Shobogans, creating the Time Lords.

Biology

 * Time Lords had red blood; mentioned that a "red carpet" was such because it was "drenched in the blood of [his] people".

Organisations

 * An early incarnation of the Doctor was recruited by The Division, an organisation which officially did not exist nor had operatives and acted against the non-interference policy of the Time Lords.
 * The Judoon possess a "cold case" unit.

Culture

 * When showing the destroyed Citadel to the Doctor, the Master references "Ozymandias", a sonnet by Percy Shelley.
 * When the Master requests an alliance with the Cyberium, he references the TV show The Apprentice, claiming he "deserves to be its business partner, because he has performed well in all the tasks", which was a common excuse used to become Lord Sugar's business partner.

Weapons

 * One death particle was able to wipe out all organic life on a planet.

Story notes

 * This episode used the same kind of "cold opening" used in Spyfall: Part Two; a recap of the preceding episode.
 * This episode had the most extensive use of archive footage in any of the Doctor Who episodes or any other media, and indeed any of the spin-offs as of 2020.
 * Tecteun's and the Timeless Child's regenerations mark the first time female to male regeneration has been seen onscreen. However, the first depiction of a female regenerating into a male in any media was in AUDIO: Enemy Lines. In the case of the Timeless Child, multiple regenerations were shown, both female to male and male to female.
 * The episode's cliffhanger ending calls back to the cliffhanger endings of both Doomsday and Last of the Time Lords, in which the dumbfounded Doctor repeatedly utters the word "what?" in response to the events suddenly and rapidly unfolding around them.
 * This episode is the first time in the show's history, discounting full red and full blue from various previous stories, that clips from the William Hartnell and Patrick Troughton eras have been shown in colour.
 * This marks the second time the theme music has been used during a TV story, playing across the Doctor's Matrix mind-blow-up sequence. The first time was in The Woman Who Fell to Earth.
 * This story confirms that the faces in the mind battle with Morbius in The Brain of Morbius are incarnations of the Doctor, something long debated amongst fans, because these 8 faces did not appear since, with following stories seemingly debunking them.
 * The Timeless Children made such a huge impact on the fandom as a whole that the episode made it into the satirical website News Thump.
 * The episode used an anagram for actor Sacha Dhawan on the Doctor Who website; "Barack Stemis" which, if re-arranged, means "Master is Back" and playing a false character called "Fakout". This tactic, discounting in-universe examples from 2007's Utopia/The Sound of Drums/Last of the Time Lords, has not been seen on television since The King's Demons in 1983. Back then it was used in the credits of the episode. Another more recent example is Mark Gatiss being credited, in the old tradition, as Sam Kisgart, for his role as a parallel universe Master, though this was more of a tongue-in-cheek reference to the classic trope than a genuine attempt at audience subterfuge.
 * This story is the third consecutive finale for an even-numbered season to feature both the Master and the Cybermen, following Death in Heaven and The Doctor Falls.
 * In the scene corresponding to the point where Tecteun's male incarnation stands alongside two other Time Lords in full high-collared regalia, the episode's script release mentions that "we can assume [the other two] might be Rassilon and Omega". 2nd assistant director Mark Corden cast himself as the Omega stand-in and hired a Don Warrington lookalike to play Rassilon, in homage to Warrington's portrayal of Rassilon in Big Finish.

Ratings

 * 3.78 million (BBC overnight)
 * 4.69 million (BBC final)

Filming locations
to be added

Myths

 * The Thirteenth Doctor would come full circle, with the pedestal holding the TARDIS key from the Meet the Thirteenth Doctor promotional teaser on 14 July 2017 appearing and the location playing a central part. (this was proven false, and the locations proving to be completely different)

Production errors

 * The extreme close-up shot of the bomb activating the death particle is in the wrong format, which causes a horizontal stretch of the image. This is due to a wrong de-squeeze of the footage filmed with an anamorphic lens.
 * When the Cyber-Master who was shot and regenerates stands up to retake his place you can briefly see that his helmet is not on correctly and the actor underneath is visible.

Continuity

 * The Master and his army of CyberMasters mimic the rallying speech of Rassilon at the end of the Last Great Time War. (TV: The End of Time)
 * The Master reminisces about assassinating presidents with the Doctor. (PROSE: Birth of a Renegade, TV: The Deadly Assassin)
 * The Master reveals the truth of the Timeless Child. (TV: The Ghost Monument, Spyfall, Can You Hear Me?)
 * The Doctor and the Master see Brendan and the Garda in "Ireland". (TV: Ascension of the Cybermen)
 * Graham and Yaz wear Cyber-suits to disguise as Cyber-Warriors, similar to the gambit Bates and Stratton attempted on Telos. (TV: Attack of the Cybermen)
 * The Doctor sees the "Ruth" Doctor within the Matrix. (TV: Fugitive of the Judoon)
 * The Master reveals that the original inhabitants of Gallifrey were the Shobogans. This is a term which, by their time, had come to be used by a group that lived outside traditional Time Lord society. (TV: The Deadly Assassin, PROSE: The Eight Doctors, All-Consuming Fire) The Shobogans themselves were a sub-group of the Outsiders. (TV: The Invasion of Time, AUDIO: Weapon of Choice, PROSE: The Eight Doctors)
 * The Master refers to the Great Cyber War, which he claims to have lived through. (AUDIO: Last of the Cybermen, TV: Revenge of the Cybermen)
 * The Master recalls fleeing from Borusa (TV: The Deadly Assassin, The Five Doctors) when they were young.
 * Long before Gallifrey's native species developed time travel, they worked on the development of interstellar travel. (PROSE: The Legacy of Gallifrey)
 * The Master double-crosses Ashad and kills him as he had done to a Cyber-Leader on the Death Zone. (TV: The Five Doctors)
 * The Master names his Time Lord-converted Cybermen under his command the "CyberMasters". Previously, transformed humanity into what he dubbed the "Master Race". (TV: The End of Time) Before that,  named himself "Cyber-Master" while posing as a converted Cybermen. (AUDIO: Master of Worlds)
 * Incidentally, Karl believed the Cybermen to be "the master race". (TV: Silver Nemesis)
 * The Master wishes he had thought of making a pun before using the Tissue Compression Eliminator on Ashad. (AUDIO: The Two Masters)
 * The Doctor's memories used to overwhelm the Matrix are of:
 * (TV: Spyfall)
 * Ashad and his Cyberguards (TV: Ascension of the Cybermen)
 * Herself absorbing the Cyberium and Team TARDIS (TV: The Haunting of Villa Diodati)
 * Rakaya (TV: Can You Hear Me?)
 * Gat, the "Fugitive" Doctor and Captain Jack Harkness (TV: Fugitive of the Judoon)
 * Herself running from Praxeus infected birds (TV: Praxeus)
 * Nikola Tesla and the Queen of the Skithra (TV: Nikola Tesla's Night of Terror)
 * A Dreg (TV: Orphan 55)
 * The TARDIS beside the ruined Capitol (TV: Spyfall)
 * A Kasaavin (TV: Spyfall)
 * The reconnaissance scout Dalek (TV: Resolution)
 * The Ux (TV: The Battle of Ranskoor Av Kolos)
 * The Solitract as Grace O'Brien and Team TARDIS in the fjord (TV: It Takes You Away)
 * A Morax and herself chained down (TV: The Witchfinders)
 * Umbreen and Prem's wedding (TV: Demons of the Punjab)
 * A Kerb!am Man (TV: Kerblam!)
 * The Pting (TV: The Tsuranga Conundrum)
 * Giant spider's webs (TV: Arachnids in the UK)
 * Rosa Parks (TV: Rosa)
 * The TARDIS and remnants on Desolation (TV: The Ghost Monument)
 * Tim Shaw (TV: The Woman Who Fell to Earth)
 * Herself choosing an outfit (TV: The Woman Who Fell to Earth)
 * Davros (TV: The Stolen Earth)
 * Rose Tyler (TV: The Stolen Earth)
 * The Sycorax leader (TV: The Christmas Invasion)
 * Donna Noble (TV: Partners in Crime)
 * A Slitheen (TV: World War Three)
 * Amy Pond (TV: The Impossible Astronaut)
 * The Abzorbaloff (TV: Love & Monsters)
 * River Song (TV: A Good Man Goes to War)
 * An animated scarecrow (TV: The Family of Blood)
 * Wilfred Mott (TV: Journey's End)
 * Clara Oswald (TV: Dark Water)
 * General Staal of the Tenth Sontaran Battle Fleet (TV: The Poison Sky)
 * Bill Potts (TV: The Pilot)
 * An Ood (TV: The Impossible Planet)
 * Martha Jones (TV: Smith and Jones)
 * Mickey Smith (TV: Boom Town)
 * The Empress of the Racnoss (TV: The Runaway Bride)
 * Rory Williams (TV: A Good Man Goes to War)
 * Jatt of the Sisters of Plenitude (TV: New Earth)
 * Sarah Jane Smith (TV: The Stolen Earth)
 * The Twelfth Doctor (TV: Listen, The Magician's Apprentice, Hell Bent)
 * The Eleventh Doctor (TV: The Almost People, The Bells of Saint John, The Rings of Akhaten)
 * The Tenth Doctor (TV: Last of the Time Lords, The End of Time, The Runaway Bride)
 * The Ninth Doctor (TV: Rose, The Parting of the Ways)
 * The War Doctor (TV: The Name of the Doctor, The Day of the Doctor)
 * The Eighth Doctor (TV: The Night of the Doctor, Doctor Who)
 * The Seventh Doctor (TV: The Greatest Show in the Galaxy, Time and the Rani, The Curse of Fenric)
 * The Sixth Doctor (TV: The Ultimate Foe, Vengeance on Varos)
 * The Fifth Doctor (TV: Time-Flight, Arc of Infinity, The Caves of Androzani)
 * The Fourth Doctor (TV: The Brain of Morbius, Pyramids of Mars)
 * The Third Doctor (TV: Planet of the Spiders, Carnival of Monsters)
 * The Second Doctor (TV: The Moonbase, The War Games, The Tomb of the Cybermen)
 * The First Doctor (TV: The War Machines, An Unearthly Child, The Name of the Doctor)
 * A Sea Devil (TV: The Sea Devils)
 * (TV: World Enough and Time)
 * A Zygon (TV: Terror of the Zygons)
 * Sil (TV: Vengeance on Varos)
 * (TV: Empress of Mars)
 * Sharaz Jek (TV: The Caves of Androzani)
 * An Auton (TV: Terror of the Autons)
 * (TV: Utopia)
 * A Voc (TV: The Robots of Death)
 * (TV: Doctor Who)
 * Sutekh (TV: Pyramids of Mars)
 * An Ogron (TV: Day of the Daleks)
 * (TV: Logopolis)
 * The Ancient One (TV: The Curse of Fenric)
 * (TV: The Deadly Assassin)
 * (TV: The Sea Devils)
 * Scaroth (TV: City of Death)
 * Various incarnations of the Timeless Child (TV: Spyfall, Can You Hear Me?)
 * Seven of the faces seen during the mindbending battle against Morbius (TV: The Brain of Morbius)
 * Brendan (TV: Ascension of the Cybermen)
 * The "Fugitive" Doctor (TV: Fugitive of the Judoon)
 * The Doctor seeks to uphold the rule "No humans on Gallifrey", echoing her reason for leaving behind Sarah Jane Smith. (TV: The Hand of Fear)
 * The Doctor mentions Percy Shelley when she takes responsibility for the Cyberium. (TV: The Haunting of Villa Diodati)
 * The Doctor returns her companions home in a TARDIS while she prepares to sacrifice herself to destroy some of her oldest enemies. Similarly, the Ninth Doctor sent Rose Tyler home in the TARDIS as he confronted the Dalek Emperor and his human-converted Daleks. (TV: The Parting of the Ways)
 * The Doctor is prepared to sacrifice herself using a weapon that cannot be remotely detonated, only for Ko Sharmus to take her place. Previously, the Tenth Doctor planned to sacrifice himself to destroy the Tenth Sontaran Battle Fleet with an atmospheric converter, but Luke Rattigan used a Sontaran teleporter to switch places with him. (TV: The Poison Sky) Before this, the Ninth Doctor offered to light the match which would stop the Gelth for the sake of Gwyneth, who silently refused. (TV: The Unquiet Dead) Earlier still, Orcini, despite the Sixth Doctor's protests, chose to hand detonate a bomb to destroy Davros' Daleks. (TV: Revelation of the Daleks)
 * Ko Sharmus was part of the resistance unit who sent the Cyberium through time and space. (TV: Fugitive of the Judoon, The Haunting of Villa Diodati)
 * The Doctor once again steals a TARDIS in order to run away from Gallifrey. (AUDIO: The Beginning, TV: The Name of the Doctor, Hell Bent)
 * The Doctor responds to being ambushed by the Judoon aboard her TARDIS by repeatedly exclaiming "what?", as the Tenth Doctor had previously done when caught by surprise aboard his TARDIS. (TV: The Runaway Bride, Time Crash, Voyage of the Damned)
 * The Doctor talks to herself at length. (PROSE: Things She Thought While Falling, TV: Orphan 55, Can You Hear Me?)
 * The Cybermen use transmats. (TV: Revenge of the Cybermen, The Pandorica Opens, Nightmare in Silver)
 * The Master once again works with the Cybermen, and is once again instrumental in creating a new race of them. (TV: The Five Doctors, Dark Water/ Death in Heaven, World Enough and Time)
 * The Cybermen again show their ability to convert the bodies of the deceased. (TV: Dark Water/ Death in Heaven)
 * The Eighth Doctor previously uncovered another secret hushed up by the Founders of Gallifrey: the role Rassilon had played in the true origin of the Ravenous. The Doctor hypothesised that Rassilon had invented the myth of their creation precisely to hide his involvement in the events on Kolstan. (AUDIO: Day of the Master)
 * The Doctor states that she had fought the Matrix before and denied its reality. The Fourth Doctor previously entered the Matrix to locate the Master after the Time Lord President was assassinated, and was forced to fight against the Matrix, which was manipulated by Chancellor Goth. (TV: The Deadly Assassin) The Sixth Doctor had also entered the Matrix after following the Valeyard and had to deal with the Matrix and its reality. (TV: The Ultimate Foe)
 * The Master had twice before secretly infiltrated and manipulated the Matrix for his ends. (TV: The Deadly Assassin, The Ultimate Foe)
 * Lady Peinforte once threatened to reveal the Doctor's secrets concerning his role on Gallifrey during the Dark Time. She believed this secret would prove the Seventh Doctor's downfall. (TV: Silver Nemesis)

Home video releases

 * This story was released on DVD and Blu-ray as part of the Series 12 boxset.