The Power of the Doctor (TV story)

The Power of the Doctor was the 2022 Doctor Who Centenary Special, broadcast as part of the BBC 100 celebrations. Marking the end of Jodie Whittaker's tenure as the Thirteenth Doctor, this was also the final entry to be penned by Chris Chibnall as showrunner. It saw the return of the Spy Master and Ashad following their apparent demise at the end of The Timeless Children, and it marked the first time the Master, the Cybermen, and the Daleks all worked together onscreen.

Several past Doctor Who companions returned for the special, most prominently Janet Fielding as Tegan Jovanka, Sophie Aldred as Ace, and Bradley Walsh as Graham O'Brien. Appearing in cameo roles were Bonnie Langford and Katy Manning as Melanie Bush and Jo Jones, with Langford returning to the television series for the first time since her exit in Dragonfire, and Manning returning to for the first time since her character's last appearance in The Sarah Jane Adventures story Death of the Doctor. Notably, joining Langford and Manning in a cameo role was William Russell as Ian Chesterton, marking the character's first appearance in the television series since The Chase in 1965, which Guinness World Records marked as the longest gap between televised appearances of a character still played by their actor.

Also returning in mental manifestations of the Doctor’s consciousness were David Bradley, Peter Davison, Colin Baker, Sylvester McCoy and Paul McGann, all reprising their roles as their respective Doctors, with Davison and McCoy also reprising their roles through an A.I. version of the Doctor — which first appeared in the 1995 novel Infinite Requiem — with Jo Martin also returning as the Fugitive Doctor through the same manner.

The story notably marked the first televised degeneration, as well as the first forced regeneration since The War Games. With the Thirteenth Doctor's forced regeneration and the Master using the name of the Doctor, Sacha Dhawan became the first actor to have portrayed both the Master and the Doctor onscreen in the same story. The special also marked the third time the Doctor was seen to regenerate more than once within the same television story, following Twice Upon a Time and The Timeless Children, and marked the first time a single incarnation of the Doctor is seen regenerating twice within the same story, and the second time a single incarnation is seen regenerating twice in their tenure following the Tenth Doctor's aborted regeneration in Journey's End and full regeneration in The End of Time.

In a twist, the special reintroduced Tenth Doctor actor David Tennant as the Fourteenth Doctor in its closing moments, marking the first time on-screen that the Doctor regenerated into a different incarnation who held the same appearance as a previous one, after such a phenomena was foreshadowed by the Curator in The Day of the Doctor, the latter having been played by Fourth Doctor actor Tom Baker.

Synopsis
Famous paintings have been mysteriously defaced around Earth, seismologists have gone missing, there is strange activity occurring in volcanoes and across the stars a bullet train is pursued by CyberMasters. The Doctor doesn't understand how it all connects. All she has is a message from an old enemy - "this is the day you die"...

Plot
On board a Toraji Transport Network bullet train hurtling through space, Train Marshal Halaz broadcasts an urgent request for help: they are being invaded by Cybermen! With her and Deputy Marshal Arnhost fighting back to save their passengers, several Cybermen fall, and the marshals consider the threat neutralised until they realise they are not just any Cybermen - they are CyberMasters and able to regenerate. Halaz increases her calls for help, only to receive a response from the Thirteenth Doctor who is ready to jump into action with Yaz and Dan, all wearing orange spacesuits.

Realising that the Cybermen are blocking the TARDIS from landing, the Doctor instead rolls out a metal ladder from the open door to the roof of the train, which she quickly realises is slightly too short, requiring a jump through open space to safety. The Doctor and Yaz make it, but Dan falters, eventually making a near-perfect landing. However, his victory is short-lived as the CyberMasters become aware of their presence, sending a group onto the roof as others search for the train's cargo. The Doctor sonics a hatch open, turning off the electromagnets and sending the CyberMasters flying into space, but at the expense of the three friends being forced to hold on for dear life. As he does, however, Dan is shot in the helmet and briefly exposed to the vacuum of space.

Back in the train, the Doctor and Yaz deal with Arnhost's injuries as Dan uses the sonic screwdriver to slow the train down. Finally, the Doctor meets with the Cyber-Leader near the cargo, revealed to be a young child. Promising to protect them, the Doctor is left in shock as the child is simply teleported away with the Cyber-Leader in tow.

Siberia, 1916. Inside a small house in the middle of a frozen landscape, a messenger asks the owner, Grigori Rasputin, for urgent help at the Winter Palace, as Tsarevich Alexei has been taken ill. As Rasputin turns to leave, however, he is revealed to be none other than, disguised with extremely long hair and beard and piercing blue eyes.

London, 2022. Inside an art gallery, Ace studies an empty wall where a painting should be. The curator insists that it has been taken down for restoration work, but Ace is less than convinced. Later, in the gallery's café, she video calls Tegan Jovanka, who is somewhere in Romania investigating a group of mysteriously missing seismologists. They note that fifteen famous paintings and twelve famous scientists have all gone missing without a trace, and Tegan is confused further by the presence of a package for her: a Russian doll box containing a toy Cyberman and a note from the Doctor, who she has not heard from in nearly forty years. Thoroughly confused, Ace decides it is time to go deeper.

The TARDIS lands outside where Dan's house should be at 37 Granger Street, Liverpool, ready to drop him off at his date as promised. However, having developed a sense of his own mortality, Dan decides that he does not want to continue and instead wants to get back to living his life, admitting that "my life's far from perfect, but... I need to get back to it. I need to attack it. And I can now... 'cause I've been with you." The Doctor reluctantly understands and returns to the TARDIS alone. Noting that he has no house after it was shrunk by Karvanista, Dan decides to go and visit his parents as he and Yaz joke about being glad to see the back of each other. Meanwhile, inside the TARDIS, a renegade Dalek contacts the Doctor, claiming to have decided the Daleks need to be destroyed due to them being a perversion of the Kaled race. It offers information about a plot to destroy humanity, promising to communicate a time and location before leaving just as Yaz enters. The Doctor tracks the young child's location to 1916 Earth but notes with dread that an extra planet has appeared in the solar system.

St Petersburg, 1916. In the Winter Palace, the Master, disguised as Rasputin, meets with Tsarina Alexandra about her son's haemophilia, which has seemingly worsened since the arrival of a second moon. He promises her that Alexei will improve soon, hypnotising her into believing him. Turning to Tsar Nicholas II, busy in thought about Russia's position in World War I, the Master hypnotises him too into taking a long holiday away with his family, leaving the Master in charge of the palace.

The TARDIS takes the Doctor and Yaz to the mysterious moon, revealing it to be a Cyber-converted planet. Before they can investigate, though, they spot a second TARDIS in the distance, with the writing on the door sign reading "HAHAHA" repeatedly. Looking inside, they find that its console has been tethered to the planet for some reason, but is indicating a second energy source outside. Sonicking away the Cybermen's cloaking shield, the Doctor discovers the child they were after, captured. Uncovering a further consciousness shield, she quickly realises it is not a child after all, but a Qurunx: an ultra-rare sentient energy being that disguised itself as something the viewer would most want to protect. The Doctor is interrupted once again by a group of Cybermen, who taunt her that she will not be able to stop their plan and that "your Master awaits" before shooting at her. The Doctor and Yaz barely manage to escape into the TARDIS before yet another distraction arises, this time a summons from Kate Stewart.

Arriving at the brand-new UNIT HQ, Kate informs the Doctor about the defaced artworks and abducted seismologists, but first allows her to reunite with Tegan and Ace, acting as new freelancers. Ace approves of her new look, while Tegan is put out at how the Doctor is now visibly younger than she is and hits back about having been abandoned by her for 38 years. Although upset by this, the Doctor identifies that all the paintings have been edited to include the Master as Rasputin's face, and he interrupts their conversation by forcing a video onto UNIT's screen. In his normal look, he announces that he is holding a conference at the International Seismology Memorial Conference in Naples and tells them to come along. The Doctor takes off, apologising to Tegan and Ace and giving them each a tap on the shoulder that bursts with static electricity before promising to return.

In Naples, the Doctor confronts the Master, giving a keynote speech to a room full of miniaturised seismologists. He explains that his dealings as Rasputin, the spare TARDIS, the cyber-planet, and the Qurunx are all "grandstanding" to attract the Doctor's attention and warn her that she will soon be erased from existence. However, he is quickly arrested by UNIT and forced into the Doctor's TARDIS before he can go any further. Yaz holds the Master at gunpoint as the Doctor promises that UNIT will keep him under armed guard.

In the midst of space, Inston-Vee Vinder hurtles out of a wormhole in a rapidly-breaking spaceship, having been on the trail of the missing Qurunx. He files a status report, admitting that although he has arrived on the cyber-planet successfully, using the wormhole was a "really bad idea" as it has destroyed his ship and left him stranded. He is shocked, therefore, to see the Master's TARDIS nearby.

The Master is apprehended by UNIT soldiers and forced into their high-security bunker, which pleases him greatly. Being watched on his way there, he takes the time to taunt his old adversaries Tegan and Ace and, with him locked up, the Doctor takes off again to meet with the Dalek traitor. Inside the TARDIS, Yaz admits her frustration once again that she is not being told any details, and the Doctor admits that she has no idea how the Master, Daleks, and Cybermen all connect.

The Doctor meets the renegade Dalek inside a volcano in Bolivia, where it allows her to extract vital data about the destruction of its race. Meanwhile, Yaz uncovers a much larger group of Daleks nearby operating heavy machinery, putting her on edge.

Inside UNIT HQ, Ace sets up a CCTV camera on the Master's cell. However, he begins to talk to them and reveals he sent a miniaturised clone of Ashad to Tegan, pretending to be the Doctor. The miniaturised Ashad enlarges and acts as a portal to bring a fleet of Cyber-Warriors into the HQ, forcing the women to hide behind a table and fire on them with gold bullets. Quickly realising this particular weakness is no longer effective, they run, and Ashad frees the Master as Kate announces that UNIT is under attack.

The Doctor discovers the Dalek traitor had been allowed to contact her by the other Daleks in order to lure her out, leaving the Daleks, including their commander, to kill the traitor and capture her. With the traitor's casing exposed, she is forced into it at gunpoint as it extends vine-like cables that force her to sit down inside before being teleported away. Yaz, meanwhile, returns to the TARDIS and, getting out her copious notes on how to control it, begs it to follow the teleport.

The Daleks take the Doctor to 1916 and hand her to the Master in the form of Rasputin, with the Cybermen in tow. Dubbing it the Master's Dalek Plan, he explains that his new "fam" has teamed up to make her undergo a forced regeneration, using Gallifreyan technology he salvaged combined with the power of the cyber-planet. While still captured, he taunts her by dancing along to Rasputin, to the surprise of even the Daleks and Cybermen, while the cyber-planet powers up and fires a beam at the palace. Meanwhile, Vinder uses his TARDIS communicator to try and ask for help from the Doctor but reaches Yaz instead. He is interrupted by a message from the Master, which Yaz urges the TARDIS to follow, allowing it to land in the Winter Palace. As the Master pushes the Doctor out of the Dalek casing and inside a narrow glass cubicle, he gets inside the second and begins the forced regeneration... to force her to regenerate into him. The cyber-planet sends its energy down into the cubicles, and despite the Doctor's desperate cries, it works. The Master finds himself, short-haired again, inhabiting the Doctor's clothes, with his previous body resting lifelessly nearby, and triumphantly declares that he is the Doctor now. Yaz exits the TARDIS and demands her Doctor back, but he refuses her while threatening her to follow him as his companion.

Back in UNIT, Kate, Tegan, and Ace run desperately from the Cybermen. Kate decides that she needs to lock down the building and urges Tegan and Ace to escape from the roof with parachutes. Just before they escape, however, Ace stops to pick up her classic bomber jacket and metal bat from when she was a teenager. As the Master fights for control of the Doctor's TARDIS, he explains that he now plans to erupt all Earth's volcanoes simultaneously to end humanity, then turn them into foundries for Daleks and Cybermen while he tarnishes the name of the Doctor. Meanwhile, Ace makes it to the roof of UNIT HQ, but Tegan refuses to go with her, accepting blame for bringing in the Cybermen. She is willingly locked inside the building.

The TARDIS lands on a distant planetoid somewhere in space, overlooking a vast scene of destruction as two neighbouring planets exchange heavy, constant fire. The Master emerges, now wearing a distorted amalgam of the Fourth, Fifth, Seventh, Tenth and Thirteenth Doctors' outfits, and proclaims to Yaz that he has stopped two sides warring by destroying them both. Spotting a hovering news camera approaching, he stoically tells it, "I am the Doctor, and I caused this". Yaz cannot bear seeing this any longer and shoves him over from behind, sprints into the TARDIS, and dematerialises, leaving him stranded. Pulling out the Second Doctor's recorder, he simply sits and waits for her to return.

The Thirteenth Doctor awakens. To her surprise, she finds herself standing in an endless rocky vista, with no landmarks except for a small boulder and a telegraph pole. Looking around, she hears a familiar voice remarking that "You're obviously one of the more determined of us". Sitting on the boulder, uncharacteristically wearing Gallifreyan robes, is the First Doctor. He remarks that she is refusing to pass through, and morphs into a visibly older Sixth Doctor to add that they need to solve her predicament so as to not ruin it for the next Doctor. Continuing to morph into older forms of the Fifth, Eighth, and Seventh Doctors, the figures describe themselves as the Guardians of the Edge; the Thirteenth Doctor is inside the Edge of Existence, a place in her mind where she would pass through upon regenerating. However, she has not yet made the journey, meaning the Master's hijacking can still be reversed. The Guardians remind her that the Master will still be vulnerable post-regeneration and that she must get help from the outside. Incredibly grateful for the help, she thanks them but notices that they have disappeared as quickly as they arrived.

Inside the TARDIS, Yaz is suddenly greeted by a Holo-Doctor. After explaining that she is an AI program the Doctor created and is responding to the emotional receptors she implanted via static earlier, Yaz explains her plan to get the real Doctor back. First, she lands on the cyber-planet and rescues Vinder, who she attempts to bring up to speed before taking off again. The Holo-Doctor explains that they have only one chance to revert a forced regeneration, and it could only work under extreme circumstances.

With a cyber-conversion pod created by Ashad in the Master's former bunker, Tegan returns to Kate, explaining that she needs to help her stop the Cybermen. After an impassioned speech, Kate relents and describes how the plan is to keep the Cybermen contained then completely level the building. A manual activation is hidden in the basement, which Tegan needs to somehow reach from the top floor. Kate distracts the Cybermen by promising them information, allowing Tegan to run. Meanwhile, Ace prepares to parachute-jump off the roof, but as she does, Ashad spots her and shoots her parachute. As she begins plummeting, the TARDIS materialises sideways on the side of the building and rescues her.

Yaz introduces Ace to Vinder as she looks around approvingly at the new TARDIS design. Yaz explains that she wants to drop Ace into the volcano in Bolivia to stop the Dalek operation. Drawing her bat, she declares it is "wicked!". Later, Yaz lands back on the planetoid to pick up the Master, seemingly apologising to him, but with Vinder hidden nearby in the TARDIS, blaster primed.

With Tegan hiding inside UNIT HQ, the Holo-Doctor appears to her, but quickly changes to become the Fifth Doctor upon reacting to her memories. He passes on a message of good luck and promises that he never forgot her after leaving her. Telling her "brave heart" one more time, he lets her go as she runs to a vast, empty lift shaft.

The Holo-Doctor next appears in front of Ace, ready to blow up the Daleks with her new Nitro-999. She again morphs, this time into the Seveth Doctor, who regretfully apologsises for falling out with her, admitting that he was just trying to teach her good habits. However, she is more than happy to make up with him, and he responds that "We're more than good. We're ace!" She heads off to fight the Daleks, but instead meets none other than Graham O'Brien, brandishing his psychic paper and proclaiming to be "Arnold Palmerson, volcano inspector" - however, it actually displays "Graham, friend of the Doctor, former bus driver, worried about the amount of Daleks in here and what he's going to do about it." The two hit it off immediately and work to destroy the Dalek volcano machine.

Kate is met by Ashad and his Cyber-Warriors. From behind a laser shield, she promises that reinforcements are on the way and that she can offer them vital knowledge of Earth. Despite Ashad's scepticism, she tells him that if he releases all UNIT staff from conversion, they can have her instead. He accepts, and she is dragged away, hoping that the Doctor will come back. Meanwhile, Tegan continues climbing down the ladder in the shaft when she slips. Ashad detects her and begins to fire, forcing her to slide down at full speed.

The Master lands the TARDIS back at the Winter Palace in 1916, telling the Daleks to start activating the volcanoes in 2022, and they begin to erupt in Bolivia, Ecuador, Indonesia, and Iceland. However, before she is killed, Yaz distracts the Master just long enough to activate the Holo-Doctor again, this time in the form of the Fugitive Doctor, who the Master does not recognise. Ordering his CyberMasters to kill the Holo-Doctor, they surround her and immediately drop dead, their shots having passed through the hologram and hit each other. Yaz and Vinder to capture the Master at gunpoint and force him to undo the Doctor's transformation, using the CyberMasters' regeneration energy to reverse the process. Knowing his time is up, he pleads with the incoming Doctor to "Don't let me go back to being me", but as the Edge of Existence begins to break down in her mind, the Doctor finally reawakens in her own body, weakened and somewhat shocked at her new wardrobe, but pleased that her hologram worked, which then disappears.

Captured by Ashad, Kate is forced into the conversion chamber and the process begins as she screams in pain. Meanwhile, the Holo-Doctor reappears to help Tegan destroy the converter. It works, and the reversal of energy attacks Ashad and the Cybermen before they convert Kate.

Back in her normal clothes in the TARDIS, the Doctor comes up with a quick fix for both the volcanoes and the cyber-planet. Meanwhile, inside the volcano, Ace takes her bat to a Dalek eyestalk and starts setting off the Nitro-999 to destroy the device. Despite their worries about making it to the surface alive, the TARDIS lands and picks them up, to the Doctor and Graham's mutual surprise, and they dematerialise just as the volcano blows up, destroying the remaining Daleks in the process.

Tegan and Kate sprint out of UNIT HQ, having activated its self-destruction, and the skyscraper collapses in on itself seconds after they escape. The TARDIS is already there to pick them up, with Tegan pushing her way in and allowing Kate her first time inside. With six companions arranged properly around the console - Tegan, Ace, Kate, Yaz, Graham, and Vinder - the Doctor tells them they all play a key part in saving the world, even though none of them fully understand what is going on, and according to Graham, Ryan is busy in Patagonia. Kate, meanwhile, is still in awe at the ship being bigger on the inside. Realising that Vinder's ship still needs fixing, the Doctor runs with him onto the surface of the cyber-planet and fixes it up, allowing him to escape while the wormhole is still there. She passes on her love to his family and lets him go.

The Doctor next makes her way into the Master's TARDIS, still in the form of her own after he burnt out most of its systems by powering the cyber-planet. Calling her companions in her TARDIS, she explains that she is using hers to jump-start his, doubling their power. They activate the controls and, as Vinder successfully escapes, the two TARDISes work together to dematerialise the entire cyber-planet and make it reappear in 2022. They then activate its conversion beams, which target the erupting volcanoes and freeze them into solid steel, saving the Earth and creating public art installations to boot. With one last problem to solve, they all land back on the cyber-planet for the Doctor to let the Qurunx free, but she asks it to use its incredible energy power to destroy the planet first. It complies, but suddenly the Master reappears, back in his original Rasputin-disguised body, badly injured and dying after the forced degeneration. Defeated, and with a cry of "if I can't be the Doctor... neither can you!", the Master channels the Qurunx's energy beam at the Doctor, mortally wounding her and causing her to begin her regeneration.

With the cyber-planet rapidly collapsing in on itself and the Master lying motionless, Yaz risks her life to grab the Doctor and return her to the TARDIS. She has one last look at her "extended fam" before passing out. When she wakes up, the TARDIS is empty save for Yaz, having dropped them all off in Croydon. Noticing that her regeneration has already started, she asks Yaz where she would go for one final trip... and what flavour ice cream she would choose.

Later, the two best friends sit eating ice cream on the roof of the TARDIS, hanging in space overlooking Earth. The Doctor eulogises about the time they spent together, claiming it to have been "so special", but admits that she needs to go on alone. With tearful smiles, they decide to not say goodbye. The Doctor takes Yaz home, landing her in a park as they share one last longing look. Yaz quickly bumps into two unexpected figures: Graham and Dan, arguing over map directions. They ask if she did not get her invite.

Yaz sits down with a group of former companions including Graham, Dan, Ace, Tegan, and Kate in a meeting room. Graham talks first, admitting that since he returned home from his travels with the Doctor, he has never been able to tell anyone on the basis of sounding mad, and wondered if there were any others who could relate to, and he was correct. Looking around at his friends, alongside Ian Chesterton, Jo Jones, Melanie Bush, and one empty chair, Graham declares that they can all share their stories together. With the mood lightening, Kate jokes that she may recruit them for some UNIT work, while Dan jokes that he already misses her, despite being pleased that he will no longer be exterminated. Ian in particular is taken about at Dan's use of the word "her", while Mel and Jo wonder how many more Doctors are out there. Meanwhile, in the TARDIS, the Doctor lands for the final time and, with her regeneration glow intensifying, tells her ship to look after the next one as she leaves to take in one last sunrise. Tegan and Ace ask Yaz if she and the Doctor are OK; Yaz responds that the Doctor will always be OK.

The Doctor finds a seaside cliff to regenerate upon. She says a fond farewell to her current self before saying to her next self, "Right then, Doctor whoever-I'm-about-to-be... Tag, you're it," and regenerates into her next incarnation. After the explosive regeneration finishes, resulting in a male incarnation once again and also a change in his clothes, the Fourteenth Doctor immediately realises something is not right. By checking his teeth, he realises out loud in a very familiar voice and accent that he actually knows the feeling of his new teeth. Alarmed by this, the newly regenerated Doctor begins to examine his new body. Recognising his new hands before noticing his predecessor's clothing has also completely been altered by the regeneration, the Doctor feels the shape of his new face and discovers to his shock that he has regenerated into a body virtually identical to his tenth incarnation. The new Doctor - or should that be the old Doctor? - can only exclaim in amazement and utter confusion, "What? What? What?!"

Cast

 * The Doctor - Jodie Whittaker, David Bradley, Colin Baker, Peter Davison, Paul McGann, Sylvester McCoy, Jo Martin
 * And Introducing David Tennant as The Doctor


 * Yaz - Mandip Gill
 * The Master - Sacha Dhawan
 * Dan - John Bishop
 * Ace - Sophie Aldred
 * Tegan - Janet Fielding
 * Kate Stewart - Jemma Redgrave
 * Vinder - Jacob Anderson
 * Graham - Bradley Walsh
 * Ashad - Patrick O'Kane
 * Deputy Marshal Arnhost - Joe Sims
 * Train Marshal Halaz - Sanchia McCormack
 * Curator - Danielle Bjelic
 * Alexandra - Anna Andresen
 * Nicholas - Richard Dempsey
 * Messenger - Jos Slovick
 * Voice of the Daleks & Cybermen - Nicholas Briggs
 * Dalek Operators - Barnaby Edwards, Nicholas Pegg
 * Cybermen - Simon Carew, Jon Davey, Chester Durrant, Mickey Lewis, Felix Young, Richard Price, Andrew Cross, Matt Doman
 * Melanie Bush - Bonnie Langford
 * Jo Grant - Katy Manning
 * Ian Chesterton - William Russell

Uncredited cast

 * Qurunx - Neo-Rae Gardener
 * Holo-Doctor - Jodie Whittaker, Peter Davison, Sylvester McCoy and Jo Martin

The Doctor's clothing

 * After stealing the Doctor's body, the Master dons the Fourth Doctor's multi-coloured scarf, the Seventh Doctor's jumper, the Twelfth Doctor's plaid trousers, and attaches a stick of celery on his lapel just as the Fifth Doctor did. He also wears one of the Tenth Doctor's ties and has the Second Doctor's recorder tucked away in his coat.
 * The Fourteenth Doctor's attire includes a white button-up shirt, with a lilac paisley tie and a loose fitting waistcoat and trousers of black and turquoise tartan. He also wears a navy blue trenchcoat and Converse shoes.

TARDISes

 * The Spy Master's TARDIS is a Type 75.

Culture

 * Among the fifteen paintings defaced by the Master are the Mona Lisa, The Last Supper, The Hay Wain, The Scream, the Girl with a Pearl Earring, and American Gothic.
 * When brandishing her bat, Ace claims that Beyoncé stole all of her moves.
 * The Master plays and dances to the song Rasputin while disguised as Grigori Rasputin.
 * The Master later plays the start of "The Skye Boat Song" on the Second Doctor's recorder.

Locations

 * While he poses as Grigori Rasputin, the Master lives in a house in Siberia, and uses the Winter Palace as his base of operations.
 * Tegan Jovanka was in Romania, somewhere near the Carpathians, when she received the miniaturised Cyberman.
 * UNIT has a new HQ in London.
 * The Master holds the International Seismology Memorial Conference in a hotel 3.2 kilometres away from Mount Vesuvius.
 * There is a UNIT base near Naples.
 * A Dalek arranges meeting with the Doctor in a volcano in Bolivia.
 * Daleks activate all volcanoes on Earth, including ones in Ecuador, Indonesia and Iceland.

Story notes

 * This story was created in celebration of the BBC's 100th Anniversary, and had the working title of The Centenary Special.
 * According to Chris Chibnall, this story was filmed in the belief that it was to be the last story of Doctor Who, as he didn't know who would take over from him. It wasn't until after filming that it was announced that Russell T Davies would be returning as showrunner.
 * Jodie Whittaker was pregnant while filming The Power of the Doctor.
 * This story shares filming locations with the Fourth Doctor story The Pirate Planet and the Seventh Doctor story The Curse of Fenric. For the latter, the landowners of the Lulworth Estate threatened to ban the BBC from filming there ever again due to what they described as them being "duplicitous and dishonest" in not describing exactly what the scene would show, potentially encouraging members of the public to put themselves in a dangerous situation, despite filming not actually taking place on top of the cliff itself.
 * Discounting regenerations shown outside of chronological order in The Night of the Doctor and The Day of the Doctor, this is the first Doctor-regeneration story since The Parting of the Ways to not take place on a Winter Special, and the first chronological Doctor-regeneration story since Journey's End to not include the word Time in the title.
 * As of this episode, the Thirteenth Doctor's tenure was able to run for longer than three Prime Ministers governing the United Kingdom (Theresa May, Boris Johnson and Liz Truss), thus making her the first ever Doctor to outlast three Prime Ministers, beating Tom Baker's record of having outlasted two Prime Minsters (Harold Wilson and James Callaghan) and failing to outlast a third (Margaret Thatcher) during his tenure as the Fourth Doctor.
 * This was the first episode to air during the reign of King Charles III, meaning that the Thirteenth Doctor's tenure was the first to cover two monarchs, with Queen Elizabeth II's death occurring on 8 September 2022, a little over a month before the Special.
 * This is the third special to air in UHD, after Revolution of the Daleks and Twice Upon a Time.
 * The new BBC logo returned to the title sequence, having been absent since Eve of the Daleks.
 * This episode is the second to have two actors' names appear at the same time in the title sequence, in this case Sophie Aldred and Janet Fielding. The first was the TV Movie which gave the honour to John Novak and Michael David Simms.
 * This story marks the first and only appearance of Daleks with standard suction cups in the televised Thirteenth Doctor era following the Reconnaissance Dalek, Defence Drone, Death Squad Daleks and Dalek Executioners, all of which wielded a form of claw manipulator, though a CGI model of a Dalek with a claw makes a cameo.
 * Whilst numerous interiors of the Dalek casing have been shown both on-screen and off-screen, the Dalek traitor notably has the Dalek mutant placed at the bottom of the middle section in contrast to the general placement within the neck section as seen in TV: The Five Doctors, Resurrection of the Daleks, Dalek, The Parting of the Ways, Daleks in Manhattan and The Stolen Earth/Journey's End.
 * The mutant itself resembles that of the Reconnaissance Dalek and its clone army from TV: Resolution and Revolution of the Daleks, respectively, rather than the earlier "New Who" mutant form introduced with the Metaltron in Dalek.
 * The Dalek gunstick as used in this story inexplicably alternate between the standard blue beams and orange beams similar to the Imperial Daleks in Remembrance of the Daleks.
 * The Master refers to his plans as the Master's Dalek Plan. This is a reversal of the 1965 story's episode title The Daleks' Master Plan, and was previously done in the title of a Big Finish Productions audio story featuring Derek Jacobi's War Master, The Master's Dalek Plan.
 * Fourth Doctor actor Tom Baker was invited to take part in the Special as one of the Guardians of the Edge, but was unavailable, with Chibnall explaining "''We asked Tom, but sadly he could not do it. He was not available. Such a shame."
 * The song Rasputin by Boney M is played during the scene where the Master, disguised as Rasputin, dances and powers on the conversion planet. This isn't the first time the Master has danced to a piece of music: he last danced to Voodoo Child by Rogue Traders in The Sound of Drums and I Can't Decide by The Scissor Sisters in Last of the Time Lords.
 * Sacha Dhawan improvised the Master's dance during the Rasputin song scene and he noted that he was given only "one or two takes" for the set piece, "and we didn't have that long to shoot it."
 * Anneke Wills was invited to return as Polly Wright to be part of the Companion Support Group, but was unavailable, saying "I heard it was quite brief so I’m glad I stayed and did my brambles instead.".
 * This story is the first non-archive, televised appearance of William Russell as Ian Chesterton since 1965 story The Chase; he had previously appeared in HOMEVID: Ian Chesterton: An Introduction in 1999. With his appearance in this episode, Russell, aged 96 at the time his scenes were shot, became the oldest actor to work on revived Doctor Who. The previous holder of this record was Ysanne Churchman, who was 92 at the time she reprised the role of Alpha Centauri in TV: Empress of Mars.
 * Additionally, with his appearance in this episode, Russell broke the Guinness World Record for longest gap between TV appearances, with GWR confirming; "The longest gap between TV appearances is 57 years 120 days, and was achieved by William Russell (UK) as the Doctor Who character Ian Chesterton in The Power of the Doctor episode, which aired on 23rd October 2022.". The achievement was previously held by Coronation Street actor Philip Lowrie as Dennis Tanner with 43 years.
 * The Thirteenth Doctor's final lines include the words "blossomiest blossom", echoing the phrase "blossomest blossom" from a 1994 interview of, and "daisiest daisy", which the Third Doctor mentioned in his speech about the Hermit in The Time Monster.
 * David Tennant holds the distinction of being the first actor to have portrayed two different numbered incarnations of the Doctor in a mainline story of Doctor Who without needing to fill in for an actor playing the new incarnation, following Sylvester McCoy filling in for the Sixth Doctor during his regeneration scene in Time and the Rani in addition to his main role as the Seventh Doctor, Paul McGann briefly acting as a body double for John Hurt's War Doctor in the closing moments of The Night of the Doctor after the regeneration of his Doctor, Tom Baker and Colin Baker portraying the Curator alongside their original incarnations, and Richard E Grant playing both the Tenth Doctor in The Curse of Fatal Death and the Ninth Doctor in Scream of the Shalka.
 * As he is playing a new incarnation rather than returning as the Tenth Doctor, David Tennant receives an introductory credit for the second time following The Parting of the Ways.
 * The end credits changed to groups instead of scrolling. This was last seen in Revolution of the Daleks. The text for the character names and crew roles were also changed to bold, last seen for the title card for The Woman Who Fell to Earth.
 * Mel is listed in the ending credits as "Melanie Bush", marking the first time on television that her surname, which was previously only established in audio and prose, has been used. Likewise, Jo is listed in the ending credits as "Jo Jones", which is the first time she was referred to as such on the credits of televised Doctor Who, with her first time being referred to and credited as such in any television media being The Sarah Jane Adventures story Death of the Doctor.
 * With this episode, all of the current-surviving actors who played the Doctor in the classic series have made an appearance in the revived series.
 * This story featured the largest number of actors to play the Doctor in a single episode, namely eight. The number increases to nine if one counts Sacha Dhawan's portrayal of the Master in the Doctor's body.
 * This is technically Paul McGann's first actual appearance in an ongoing television production of Doctor Who - his first turn as the Eighth Doctor was in a made-for-TV movie, while his second was a minisode. Discounting archive footage used in episodes such as The Next Doctor and The Eleventh Hour, McGann had not yet starred in an actual episode of the series.
 * This is the last story to be composed by Segun Akinola, who joined in The Woman Who Fell to Earth in 2018 after Murray Gold decided to leave the show after 12 years in Twice Upon a Time in 2017.
 * Due to a licensing deal between the BBC and Disney Branded Television to have future Doctor Who stories stream on Disney+, this was the final episode to air on BBC America.
 * Russell T Davies revealed to Doctor Who Magazine #584 that "[he] was very certain that [he] didn’t want David to appear in Jodie’s costume." explaining that his reason for the Doctor's clothes changing during regeneration was to avoid stereotyping "the notion of men dressing in "women's clothes", the notion of drag", describing it as a "very delicate" matter, expressing that "it has to be done with immense thought and respect", and that the media would make it "look like mockery" of that culture, as Tennant is taller than Whittaker.
 * Jodie Whittaker's half of the regeneration was filmed at Roath Lock Studios on 13 October 2021, edited by Rebecca Trotman. The post-regeneration scene with David Tennant as the Fourteenth Doctor was filmed separately at Wolf Studios in Cardiff on 13 May 2022, directed by Rachel Talalay, edited by Adam Green and co-written by David Tennant and Russell T Davies.
 * The line "I know these teeth" in the post-regeneration scene was scripted by David Tennant himself.
 * For Red Nose Day on 17 March 2023, Tennant appeared in-character as the Fourteenth Doctor in a Comic Relief 2023 sketch. The sketch was a re-enactment of the regeneration sequence, with Lenny Henry about to get ready to host the live-show, but claims to feel sick and regenerates into Tennant.
 * According to Chris Chibnall on the DVD and Blu-ray commentary, the idea that Tegan and Ace became friends was the idea of their respective actresses.
 * David Tennant and David Bradley had previously appeared in Chris Chibnall's Broadchurch, which also featured Jodie Whittaker.
 * The two actors also appeared in Blackpool and Harry Potter and the Goblet of Fire.
 * While Tennant's involvement with the 60th anniversary specials had been known before this story's broadcast, it wasn't confirmed until the end of this story that Tennant would be returning as a separate incarnation from the Tenth Doctor, with returning showrunner Russell T Davies confirming this incarnation to be the Fourteenth Doctor, although speculation and rumours surrounding Tennant's return, in particular about him being the next Doctor, had been circulating online for months before The Power of the Doctor had aired.

Contradictions with expanded media

 * This story touches on the circumstances of Ace leaving the Seventh Doctor's company, an event which was not seen on-screen, but had been recently depicted in the novel At Childhood's End, written by Sophie Aldred herself. However, The Power of the Doctor contradicts At Childhood's End by having Ace meet the Thirteenth Doctor, Yasmin Khan and Graham O'Brien for the first time, though At Childhood's End does establish that Ace's timeline has multiple possible futures.
 * Tegan's claim that she hasn't seen the Doctor since 1984 contradicts the Big Finish audio The Gathering, where the Fifth Doctor catches up with her in 2006 just as she's about to celebrate her 46th birthday. It also contradicts the date given by PROSE: Fixing a Hole, which states she shared an adventure with the Sixth Doctor on 23 February 1985, as depicted in A Fix with Sontarans.
 * Clyde Langer had said that Tegan and Nyssa were a couple in Farewell, Sarah Jane. Here, Tegan mentions having two ex-husbands, but Nyssa isn't mentioned at all.
 * When the Thirteenth Doctor met the renegade Dalek inside the TARDIS, she claimed that she had never met a Dalek that would turn against its own race hence her saying: "Well, this is new." However, this contradicts the fact that she had previously met Rusty in her previous incarnation in Into the Dalek and Twice Upon a Time.
 * Ace claims the last time she saw the Master, he was "half-cat", referring to Survival, ignoring the Virgin New Adventures story First Frontier, the Big Finish audio story Dust Breeding and the Titan Comics Crossing the Rubicon.
 * AUDIO: The Light at the End was excused as the story was set in an alternate timeline, which altered Ace's memory of her experience and encounter with the Master in the story. Additionally, the story hints that it was set before Survival from the Seventh Doctor and Ace's perspective as Ace stated she didn't know who the Master was.

Details from script release

 * The bullet train pre-credits sequence has many changes:
 * The CyberMasters entered in the wrong carriage because Train Marshal Halaz deliberately shuffled the carriages.
 * On the train, Dan and Yaz reminded the Doctor that she forgot to tell them the plan.
 * When Dan's helmet got hit, his face got suctioned toward the rupture and his nose plugged the gap.
 * Dan's departure speech was completely different, with the Doctor giving a response.
 * During its first meeting with the Doctor, the Dalek traitor revealed more of its background such as identifying itself as an elite biological combat engineer whose mission was to devise strategies to ameliorate any Dalek defeat in battle, its work resulting in a genetic code which was to activate and self-execute Dalek creatures in the event of a threat to Dalek supremacy in battle, causing their casings to flood with toxic radiation and detonate, fatally damaging all enemies within a broad radius.
 * To start the Rasputin song, the original scene had the CyberMasters activate panels on their arms and the Master used an old iPod to play the music instead of the TCE.
 * Originally, three planets were at war instead of two and the devastation would be seen up close.
 * The Eighth Doctor Guardian was seen as a separate figure instead of being part of the one figure in the final version.
 * The original script had the Master arrive in the Tunguska forest in Russia in 30 June, 1908. Additionally it had a whole scene with a Russian woman watching in horror as the "first experiment" with the cyber-planet went wrong and squashed many miles of forest. The Master claimed he sent himself to Siberia as "punishment".
 * Tegan was seen more heavily injured after her fall, with an injured her ankle and wrist, whereas she only had a slight limp in the final version.
 * The feedback was revealed to only have knocked Ashad unconscious and an additional scene showed Ashad wandering the UNIT hallways as the building collapsed around him.
 * The original script had a scene, set after he was returned to his old body, with the Master as Grigori Rasputin meeting with Russian Prince Yusopov, who, in keeping with historical fact, would have "Rasputin" shot and put in a sack by two henchmen to be dumped in the river, only the bullets were not seen hitting.
 * During the Companion Support Group scene in the script the laptop was suggested to be for Martha Jones, Ryan Sinclair or, somehow, Jackie Tyler.
 * The Thirteenth Doctor's final scene in the script was originally different, with the Doctor sitting rather than standing, and her last lines being switched around, with her final words being, "I bet it's going to be brilliant.", echoing back to her first words "Oh, brilliant." in TV: Twice Upon a Time.
 * Due to the fact that Chris Chibnall did not know anything about the future of Doctor Who, the regeneration scene was initially left open ended, with the last shot being the Doctor mid-regeneration.

Ratings

 * Overnights: 3.71 million
 * Regeneration: 4.04 million
 * Consolidated: 5.30 million

Myths

 * Yasmin Khan would be a victim of the Tissue Compression Eliminator. (This turned out to be false. The rumour started when a promotional picture was released of Sacha Dhawan as the Master holding a tiny figurine resembling Yaz)
 * Dan Lewis would die. (This ended up being false. The rumour came about as no promotional material depicted Dan outside the space bullet train mission)
 * Kate Stewart would either die or be converted into a Cyberman. (Both of these ended up being false. Although she was shown going through the conversion process, which was halted by Tegan)
 * Vinder and Bel were to be revealed as the Doctor's parents. (This was proven false [this rumour had been circulating since "Once, Upon Time"])
 * The Doctor was to regenerate on top of a cliff or drown in the ocean. (Cliff was proven true)
 * The Doctor's regeneration was triggered by being shot by Yaz, who was under the influence of the Master. (This was proven false, although the Master was responsible for the Doctor's regeneration)

Filming locations

 * Dan-yr-Ogof caves, Powys, Wales - Bolivian caves
 * Durdle Door, Lulworth, Dorset - Regeneration cliffside (green screen)
 * Hodge House, Cardiff - UNIT HQ interior
 * The Gate, Cardiff - International Seismology Memorial Conference interior
 * Grange Gardens, Cardiff - the Thirteenth Doctor drops off Yaz with Dan and Graham
 * Bristol Museum and Art Gallery - Ace notices a painting is missing
 * Llanmaes Street, Cardiff - Dan leaves the TARDIS for the final time in Liverpool
 * West Bute Street, Cardiff - Kate and Tegan comment on the destroyed UNIT HQ
 * Hebron Hall Christian Centre, Dinas Powys - Companion Support Group meeting place

Production errors

 * The Master's incarnation of the Doctor loses the Thirteenth Doctor's earring after changing his clothes. It momentarily returns during one scene, before disappearing once more until Jodie Whittaker's return to the role where it returns permanently without explanation.
 * The Doctor says that 2022 is in 'the second decade of the 21st century'. It's the third.
 * On the ABC, "Qurunx" was misspelt as "Quaranx" in the subtitles.

Continuity

 * Dan is preparing for another date with Diane, (TV: The Halloween Apocalypse) who he got back into contact with after his adventure with Madam Ching. (TV: Legend of the Sea Devils)
 * Tegan last saw the Doctor "thirty-eight years ago" in 1984. (TV: Resurrection of the Daleks)
 * Dan's house has still not recovered from being shrunk by Karvanista. (TV: The Halloween Apocalypse)
 * The Dalek traitor mentions the Dalek casing originally being forged to ensure the survival of the Kaled race before their mission was perverted into conquest following the Kaleds' extinction. (TV: Genesis of the Daleks)
 * The Doctor references Davros without mentioning his name, as before in the ninth and tenth incarnations. (TV: Dalek, Evolution of the Daleks)
 * The Doctor recalls the Master creating the CyberMasters on Gallifrey. (TV: The Timeless Children)
 * Kate is rebuilding UNIT following the defeat of the Grand Serpent, (TV: The Vanquishers) who had orchestrated the organisation's shutdown as part of his alliance with the Sontarans during the Flux Offensive. (TV: Survivors of the Flux)
 * The Doctor asks the Master how he escaped Gallifrey, (TV: The Timeless Children) which he mentions having "ransacked". (TV: Spyfall)
 * The Master still has the Cyberium inside him. (TV: The Timeless Children)
 * The Master taunts Tegan by mentioning her Aunt Vanessa, who he killed when they first met, (TV: Logopolis) while Ace recalls that the Master was "half-cat" the last time they met. (TV: Survival)
 * The Master mentions that he killed Ashad. (TV: The Timeless Children)
 * Ace remembers the Cybermen's weakness to gold, (TV: Silver Nemesis) and UNIT has guns with gold bullets, (TV: Battlefield) but Ashad reveals that the Cybermen have overcome this weakness. (TV: Nightmare in Silver)
 * Kate putting the UNIT headquarters into lockdown mirrors how, when Lisa Hallett rampaged throughout Torchwood Three, Jack Harkness ordered Toshiko Sato to initiate lockdown and warned that a single Cyberman must never escape to the outside world. (TV: Cyberwoman)
 * Yaz has post-it notes on how to fly the TARDIS, (TV: Revolution of the Daleks) one of which makes note of Huon energy. (TV: The Runaway Bride)
 * The Master says that he has "dressed for the occasion" of taking the Doctor's body. (TV: Doctor Who)
 * The Master is aware of the Time Lords enforcing a regeneration onto the Second Doctor, (TV: The War Games; COMIC: The Night Walkers) and wonders if they did the same to the Timeless Child. (TV: The Timeless Children)
 * Vinder uses the communications device the Doctor gave him. (TV: Once, Upon Time)
 * The Master has attempted to take the Doctor's body before. (TV: The Keeper of Traken, Doctor Who)
 * The Master says, "I would hate to bring you down to size", to Yaz when entering the TARDIS in the Doctor's body, similar to what he said he "should have said" when he killed Ashad with the Tissue Compression Eliminator. (TV: The Timeless Children)
 * After she is forced to regenerate, the Doctor sees her previous incarnations as the Guardians of the Edge in her mind, just as the Eighth Doctor had seen manifestations of his three predecessors within his mind after Charley Pollard stabbed him with an anti-time sword and he was at risk of regenerating. (AUDIO: Zagreus)
 * The Doctor makes use of the Holo-Doctor that the Seventh Doctor had once given to Bernice Summerfield. (PROSE: Infinite Requiem)
 * When she first sees the Holo-Doctor, Tegan believes she is hallucinating. According to one account, she would come to believe that her travels in the TARDIS had been an fantasy she concocted to deal with Vanessa's death. (PROSE: Good Companions)
 * Tegan confides to the Fifth Doctor's image that seeing the Cybermen makes her think of Adric. (TV: Earthshock)
 * Graham still has his psychic paper. (TV: Revolution of the Daleks)
 * Ace recalls fighting the Daleks in 1963. (TV: Remembrance of the Daleks)
 * Yaz recognises the Fugitive Doctor as Ruth Clayton, a tour guide she met in Gloucester. (TV: Fugitive of the Judoon)
 * The Holo-Doctor calls the Master "a rubbish schoolboy", which coalesces with the Seventh Doctor recalls getting better grades than him (PROSE: Survival) and the Eighth Doctor's comments on the Master's academic prowess. (AUDIO: Masterplan)
 * Ace blinding a Bronze Dalek before Graham uses one of her Nitro-9 mirrors a similar tactic done on a Grey Dalek by the Sixth Doctor and Peri Brown at Tranquil Repose on Necros. (TV: Revelation of the Daleks)
 * The Doctor places Yaz, Ace, Tegan, Kate, Vinder and Graham to various positions within the TARDIS around its console to be given responsibility to handle a part of the controls to help her save the day, which resembles when the Tenth Doctor showed the Children of Time a part of the TARDIS to help bring the Earth back to where it belongs. (TV: Journey's End)
 * Yaz mentions that she tried to take everyone home, but dropped them off in Croydon instead, calling it "close enough." While attempting to return Sarah Jane Smith home, the Fourth Doctor accidentally dropped her in Aberdeen instead of Croydon. (TV: The Hand of Fear) When told of his mistake, the Tenth Doctor asked if they were close. (TV: School Reunion)
 * Graham organises a support group meeting of some of the Doctor's past companions, just as Alice Obiefune once did. (COMIC: The Meeting)
 * The Doctor remarks on the "blossomiest blossom", akin to the Third Doctor's recollections of the "daisiest daisy". (TV: The Time Monster)
 * The Doctor's clothes change when they regenerate for the first time since the Second Doctor emerged from the First Doctor's regeneration. (TV: The Power of the Daleks)
 * The Fourteenth Doctor remarks on his familiar teeth, (TV: The Parting of the Ways) and repeats the word "what" in triplicate. (TV: Doomsday, The Shakespeare Code, Last of the Time Lords, Time Crash, Music of the Spheres)
 * Tegan is taken back by the Doctor's young appearance. Jo was similiarly surprised when she reunited with the Doctor and said to Sarah Jane she felt they changed into a baby's face (TV: Death of the Doctor)
 * The Daleks, Cybermen and the Master have worked together once before. (PROSE: Special Occasions: 1. The Not-So-Sinister Sponge)
 * The Curator's prediction to the Eleventh Doctor that they might end up revisiting a few old faces in the years to come had happen when the Thirteenth Doctor regenerated into an incarnation that resembled a slightly older version of the Tenth Doctor. (TV: The Day of the Doctor)
 * Tegan initially stated that she had not seen the Doctor in 40 years, but then stated it had been 38. When Sally Sparrow stated her disbelief that the Doctor would know what she would say 40 years before she said it, the Doctor quickly corrected her by telling her "38". (TV: Blink)
 * Alexandra comments that the haemophilia in her son, Alexei, has worsened since the "second moon [arrived] in the sky". The Tenth Doctor and Rose Tyler speculated that Victoria first developed haemophilia, potentially a form of lycanthropy, after being bitten by the Lupine Wavelength Haemovariform. Alexei is one of her descendants. (TV: Tooth and Claw )