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Ncuti Gatwa
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Don't Move!
Don't Move!
 Caught in the middle of a devastating war on Kastarion 3, The Doctor is trapped when he steps on a landmine.

 Can he save himself and Ruby, plus the entire planet... without moving?

Source: BBC Website

General Information

Season: Forty One (New Series 14)
Production Code: 14-3
Story Number: 307 (New Series: 151)
Episode Number:878 (New Series: 182)
Number of Episodes: 1
Percentage of Episodes Held:100%
Production Dates: March 2023
Broadcast Date: 18 May 2024
Colour Status: HD Colour
Studio: Wolf Studios (Cardiff, Wales)
Writer:Steven Moffat
Director:Julie Anne Robinson
Producer:Vicki Delow
Executive Producers:Jane Tranter, Joel Collins, Julie Anne Robinson, Julie Gardner, Phil Collinson, Russell T Davies and Steven Moffat
Production Executive for BBC Studios:John Hamer
Executive Producer for the BBC:Rebecca Ferguson
Commissioning Editor for the BBC:Lindsay Salt
Co-Producer:Ellen Marsh
Script Supervisor:Nicki Coles
Script Editors:Scott Handcock and Rosheed Bello (Assistant)
Editors:Tom Hodges BFE, Emily Lawrence (Assistant), Joseph Keirle (Assistant) and Matt Nathan (VFX)
Colourist:Gareth Spensley
Production Executive:Steffan Morris
Junior Production Executive:Charlotte Cox
Production Manager:Delmi Thomas
Post Production Producer:Ceres Doyle
Post Production Supervisor:Liv Duffin
Location Manager:Baljinder Sidhu
Supervising Location Manager:Iwan Roberts
Studio Manager:Richard Balshaw
Unit Manager:Kyle Yates
Production Designer:Phil Sims
Director of Production:Emily Russell
Director of Photography:Tobias Datum
Casting Director:Andy Pryor CDG/CSA
Online Editor:Christine Kelly
Line Producer:Mark Devlin
Costume Designer:Pam Downe
Hair & Make-Up Designer:Claire Williams
Cameramen:James Chesterton ACO (Operator), Andrea Jovanovska (Trainee) and Chai Lee Tan (Trainee)
Construction:4Wood TV & Film
Virtual Production:Pixomondo
Visual Effects:Goodbye Kansas
VFX Producer:Will Cohen
VFX Supervisors:Dave Houghton and Jim Parsons
Additional VFX:BBC Wales Graphics
Special Effects:Real SFX
Stunt Co-ordinators:Andy Godbold and Derek Lea
Stunt Performers:Ayesha Hussain, Gary Grundy, Jessica Barfoot, Lucy Fowl, Luke Gomes and Paul Joseph
Choreographer:Jack Murphy
Incidental Music:Murray Gold
Sound Recordist:Alex Thompson
Re-recording Mixer:Paul McFadden
Music Conducted By:Alastair King
Music Performed By:BBC National Orchestra of Wales
Music Supervisors:Ollie White and Marnie Davidge (Assistant)
Title Sequence:Painting Practice & Realtime Visualisation
Title Music:Ron Grainer and the BBC Radiophonic Workshop. Arranged by Murray Gold
Number of Doctors: 1
The Doctor: Ncuti Gatwa (The Fifteenth Doctor)
Number of Companions: 1The Companion: Millie Gibson (Ruby Sunday) Additional Cast: Joe Anderson (John Francis Vater), Majid Mehdizadeh-Valoujerdy (Carson), Caoilinn Springall (Splice Alison Vater), Varada Sethu (Mundy Flynn), Bhav Joshi (Canterbury James Olliphant), Susan Twist (Ambulance)Setting: Planet Kastarion 3 (5th October 5087) Villain:Ambulance

The Episodes

No. Episodes Broadcast
Duration Viewers
In Archive
878Boom18 May 202444'44"3.6Yes

Total Duration 45 Minutes

Audience Appreciation

Average Viewers (Millions) 3.6


 This story exists and is held in the BBC's Film and Videotape Library.

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"Boom" was written by Steven Moffat, who had previously been Head Writer and Executive Producer for Doctor Who from 2010 to 2017. This story was directed by Julie Anne Robinson.

This story revolves around the Fifteenth Doctor (Ncuti Gatwa) and his travelling companion, Ruby Sunday (Millie Gibson), arriving on an alien planet in the midst of a large-scale war. When The Doctor accidentally steps on a landmine, he is forced to come up with a solution to disarm the device before it detonates - without moving.

It has been seven years since Steven Moffat last delivered a Doctor Who script, his last being "Twice Upon a Time". He was invited to return to the show by the incumbent showrunner, Russell T Davies, after his own return to Doctor Who.

Steven Moffat has been described as one of the show’s great masters and has written some of the most popular stories. So the expectation for this story was high and promised to be one of the true highlights of Season Forty One (New Series 14).

Historically, his one-word story titles have been some of the cleverest and most cerebral in the show’s history (these include "Blink" and "Listen").

As well as previously running the show Steven Moffat has previously written stories for Russell T Davies during his first time as showrunner. However, Steven Moffat's return marked this story as the first that a previous showrunner for Doctor Who has returned to write a story for a successive showrunner. This story is also the first story in which Russell T Davies is not credited as a writer for the show since his return with "The Star Beast".

It has been revealed that Steven Moffat was inspired to write this story from a scene in the first episode of the 1975 Dalek story "Genesis of the Daleks" in which the Fourth Doctor steps on a landmine while traversing a battlefield on the planet Skaro.

When conceptualising this story, Steven Moffat felt that The Doctor managed to escape from the predicament in "Genesis of the Daleks" a little too easily and wanted to expand on this concept to span a whole story. He also hoped to create a suspenseful story, feeling that it was one genre the show had not previously explored.

Steven Moffat has stated that he began writing a rough version of this story in late 2021 before officially telling the production office he had accepted Russell T Davies’ offer. He also revealed that after writing the first 12-14 pages of the script, he believed the story didn't start in the proper place and so decided to start afresh.

This story features a previously unannounced appearance by Varada Sethu, who portrayed the part of Mundy Flynn. Varada Sethu had previously been announced as a future travelling companion for the next season. Varada Sethu later revealed that she was not cast for Season Forty Two (New Series 15)) until well after this story had completed filming. Russell T Davies confirmed that Varada Sethu's companion character would not be Mundy Flynn but he has suggested that there would be an eventual connection between the two characters. Steven Moffat compared the appearance to that of Jenna Coleman's Clara Oswald, a former companion of the Twelfth Doctor who was announced as a companion and who appeared as a slightly different, although connected character, a year earlier than expected.

Susan Twist portrayed the face on the screen of the Ambulances depicted in this story. Susan Twist has also made appearances in other stories in this season as seemingly disparate characters (as a tea lady in the previous story "The Devil's Chord" and as a hiker in the following story "73 Yards"). Susan Twist was also cast as Mrs Merridew in last season’s Fourteenth Doctor story "Wild Blue Yonder". The remainder of the cast for this story was made up by: Joe Anderson, Majid Mehdizadeh-Valoujerdy, Caoilinn Springall, and Bhav Joshi.

This story is considered to be a bottle episode as it was filmed entirely on two sets built at Wolf Studios in Wales and featured a limited cast.

The read-through for the story took place on the 1st March 2023. Steven Moffat assumed the role of Executive Producer and led meetings that determined the tone of the story before filming began.

This story was filmed in the third production block along with "Space Babies". Director Julie Anne Robinson chose to film this story scene-by-scene rather than out of order as typically done. She also chose to film longer takes than what is usually done - some of which lasted up to seven minutes.

The production team needed a crater with which they could film for up to 20 days. They considered filming on-location and scouted many quarries including Parys Mountain in Wales. Production Designer Phil Sims ultimately decided to build the set on a soundstage at Wolf Studios to avoid the possibility of inclement weather.

The encampment set was constructed on the backlot at Wolf Studios and utilised shipping containers and the external wall of the actual studio as a backdrop. The remainder of the fictional alien planet was made using computer-generated imagery that was viewed on a large LED display.

The Doctor confirms that ‘The Doctor’ is not his real name and that he is not even a real doctor.

The Doctor confirms having been a father, something his tenth incarnation told Rose Tyler in "Fear Her" and Donna Noble in "The Doctor's Daughter".

The Fifteenth Doctor does not seem to wear a regular outfit like his predecessors. The only constant so far in The Doctor's attire are the rings on his fingers.

The Doctor mentions that fish fingers and custard is his favourite dish. This dish was first mentioned as The Doctor’s favourite, as revealed by the Eleventh Doctor in "The Eleventh Hour" and again in "Let's Kill Hitler".

Snow is again seen falling around Ruby when she is in peril. This has happened to her several times (see "Space Babies" and "The Devil's Chord") with The Doctor once more noting the significance of this when she was left, as a baby, outside the church in "The Church on Ruby Road".

In this story The Doctor encounters Anglican Marines who are members of The Church. He reveals that he will be ‘popping in’ on them occasionally. The Eleventh Doctor had many encounters with their members, such as during the events in "The Time of Angels/Flesh and Stone", "A Good Man Goes to War" and "The Time of The Doctor".

This story expanded on the concept of a fictional company called Villengard that manufactures weapons, which was first mentioned in the 2005 Ninth Doctor story "The Empty Child/The Doctor Dances" that was also written by Steven Moffat.

The Doctor has been to Villengard before. This occurred, when he was known as the War Doctor, in the comic "The Whole Thing's Bananas". The Ninth Doctor also mentioned Villengard to Captain Jack Harkness in "The Empty Child/The Doctor Dances". The Twelfth Doctor later found the planet in ruins in "Twice Upon a Time".

The Doctor mentions that he once attempted to disarm an inactive Villengard smartmine for a bet. He failed to disarm the mine so losing the bet.

The Doctor is heard singing The Skye Boat Song. The Second Doctor can be heard playing this song on his recorder in "The Web of Fear". The Master also is heard singing this song in "The Power of The Doctor". This song dates back to an adaptation of the Gaelic song from 1782.

The poem about the President's wife does not exist in real life - it references a quote from Missy in "The Magician's Apprentice/The Witch's Familiar" where she tells Clara Oswald that she cared about him ‘since the night he stole the moon and the President's wife’. The Twelfth Doctor also recounted ‘stealing and losing the moon’ during "Heaven Sent/Hell Bent".

The Doctor breaks the fourth wall again when he is seen saying direct to the camera (and so the viewer): ‘we all melt away in the end’. The Doctor has broken the fourth wall before. This first occurred during the seventh episode of the 1965/66 First Doctor story "The Daleks' Master Plan" called "The Feast of Steven" and several times after.

This story had an overnight viewing figure of 2.04 million during its broadcast on BBC One. Despite being the highest-viewed programme on BBC One for the day this story was down almost 200 thousand viewers from the previous story, "The Devil's Chord".

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The Plot

WARNING: May Contain SpoilersHide Text

In 5087, on the war-torn alien planet of Kastarion 3, injured soldier John Francis Vater of the Anglican Marines wanders through a desolate battlefield. Blinded, he relies on the assistance of his orderly, Carson, to lead him to safety. As they walk, he contacts his young daughter, Splice, back at the Church's base. He assures her he is on his way back to her and implores her to brush her teeth, before ending the call.

The pair halt as they realise that a robotic Ambulance is close by. Carson warns John that they should avoid it, fearing it will deem him unfit for military service, but John insists they have no choice. As they continue Carson slips down a steep slope and steps on a landmine, which vaporises him. The noise alerts the robotic Ambulance, causing it to approach John. It latches onto him. Ambulance scans him, diagnosing that his blindness means his life must be terminated. John tries to resist, citing that his daughter needs him. The Ambulance insists, smelting him away.

Nearby the TARDIS has materialised and The Doctor, on hearing John's cries, races out of the TARDIS with his travelling companion Ruby Sunday following him. However, The Doctor also steps on a landmine. As the green scanner starts counting down The Doctor begins to sing ‘The Skye Boat Song’. Hearing the song, Ruby approaches him, finding The Doctor standing with one leg on the landmine and his other leg in the air. The Doctor remarks that he used the song to calm himself to prevent the detonation, believing the landmine (that he has recognised has come from Villengard a weapons manufacturing company) is scanning for signs of life to determine what has stood on it; by calming himself, he is tricking the landmine into thinking he is not there, but one wrong move and - boom!

John Francis Vater
John Francis Vater

The Doctor instructs Ruby to go find a rock, or something else heavy, so that he can counterbalance his weight when he tries to put his back down on the ground. Nearby Ruby finds a strange heavy cylinder, not realising at first that this is the compressed tissue of John. The Doctor sees that Ruby has found a possible suitable object and asks her to toss it into her other hand. This allows The Doctor to calculate if it is heavy enough for him to use to counterbalance himself. Confident that it will, he orders Ruby stay away and to toss it to him. Ruby though argues that there would be a better chance of success if she hands it to him. The Doctor at first refuses but eventually gives in, agreeing to Ruby's request to sing the song again to maintain a rhythm that will allow her pass the cylinder to him at exactly the same time he sets his other foot down.

This the succeed to do without detonating the landmine and now that he is a more stable position The Doctor takes a closer look at the cylinder that Ruby found and reads the name John Francis Vater on a plaque. Upon speaking the name, a holographic reconstruction of John appears and asks that his remains be returned to his next of kin. The Doctor and Ruby asked what happened to the man, and find out that he was terminated upon discovery of his blindness. The Doctor deduces that John's continued survival would have only harmed the budget and wellbeing of the mission, and so the algorithm dictated that he was to be terminated.


As the hologram fades away, John’s daughter Splice arrives at the crater looking for her father after having received the message from her father earlier and tracking it back to its source. The Doctor and Ruby look around nervously and introduce themselves to her. When Splice introduces herself John Francis Vater's hologram whirs back to life and starts talking to her, apologising for her loss. Splice though does not understand and on seeing what she thinks is her father she starts to run towards him and so towards The Doctor and the landmine. Ruby is forced to keep Splice away so she won't trigger the landmine. The situation though has caused the timer on the landmine to countdown further as The Doctor struggles to keep himself calm.

Then an Anglican Marine arrives and from above the crater insists that The Doctor release the casket that he is holding, as it contains the remains of an ordained Anglican. With her gun still trained on The Doctor the marine, Mundy Flynn, explains that they are fighting Kastarion aliens that are thought to be living underground. She says that there is no reason for him not to release the remains of John Francis Vater to her as The Doctor is dead already. She explains that even if the landmine does not detect a viable target it will still explode after a certain time as a failsafe. So as to keep calm The Doctor banters back at her. Mundy though is not amused by this and determined to make him drop the casket she shoots The Doctor’s arm but The Doctor holds on regardless, enduring the pain as the timer on the landmine countdowns further again.

The Doctor asks Mundy how the landmine actually works, since he recognises that it does not have an explosive component. Mundy explains that the landmine is triggered by affecting the DNA of whoever steps on it and turning them into the explosive. The Doctor reveals that as he a Time Lord this means his biology will create an explosion far bigger than she expects. She scans him and determines that he is right; he could wipe out half the planet. However, Mundy's attack has injured The Doctor, prompting an Ambulance to enter the crater and scan The Doctor. Panicked, Ruby takes Mundy's rifle and fires it into the air to draw the Ambulance away from The Doctor so that it doesn't treat him. But Mundy reveals that this will only work if one of them is injured as well. Revealing that her gun is on its weakest setting, she hands it over to Ruby and orders her to shoot her arm. As Ruby hesitantly aims the gun at Mundy another Anglican Marine called Canterbury James Olliphant (also known as Canto), who harbours a crush on Mundy, arrives and, believing Ruby is about to kill Mundy, shoots Ruby, leaving her severely injured.

Activating a Mine
Activating a Mine

This though does result in the Ambulance switching its focus from The Doctor to Ruby. Ambulance identifies Ruby’s age but cannot locate her next of kin, stumbling again and again. As it tries snow begins to fall. Then the snow stops, freezing in mid-air. The Ambulance determines that Ruby has approximately 432 seconds to live, but as she's not ordained, withholds treatment. Mundy and Canto try to save Ruby, to keep her alive, but the Ambulance is programmed to not heal unbelievers.

The Doctor, having deduced earlier, reveals the truth: there are no Kastarions and Villengard is making money simply off the soldiers being there. To save Ruby, to stop the landmine from going off and the Ambulances killing anyone else the Anglian Marines need to surrender. He explains that when the marines arrived six months ago and set up their defensive perimeters, they launched the Ambulances' acceptable casualty algorithm. Doing this they set in motion a cycle of attrition and war against their own hardware, grinding themselves down just enough to keep themselves engaged, keeping the combat ongoing, and keeping the money flowing to Villengard. Mundy though is sceptical and demands proof, and so The Doctor calls for John Francis Vater's hologram, ordering him to enter into the Ambulance's computer to find proof that the planet is uninhabited and the deaths are entirely self-inflicted. John Francis Vater insists that this goes against his protocols, but The Doctor insists he is still Splice's father and has a duty to help her. John finally relents, reminds his daughter to brush her teeth, and disappears into the Ambulance.

While trying to reconfigure the Ambulance treating Ruby, Canto is killed. In his cylinder, Canto admits to Mundy how much he loves her. Other Ambulances then arrive surrounding the crater, the Algorithm having sent them to prevent a data breach, claiming it had destroyed John Francis Vater's hologram. The landmine beneath The Doctor's feet begins its failsafe detonation process, meaning the planet will explode. Then all the Ambulance's begin to glitch as it is revealed that John Francis Vater's hologram has managed to override their protocols, resulting the lead Ambulance to heal Ruby. The landmine also turns green, meaning The Doctor can safely step off it.

A short time later, The Doctor explains that John's love for his daughter defeated the Ambulances. As the group admire the sky the marines prepare to leave the planet, the false conflict now over. However, The Doctor soon gets bored and insists he and Ruby depart. As they return to the TARDIS, The Doctor and Ruby look back towards Splice and Mundy who are admiring the sky (Mundy having previously promised John that she would look after Splice). Alongside them is John Francis Vater's hologram who waves The Doctor and Ruby goodbye.

The Doctor
The Doctor
Ruby Sunday
Ruby Sunday
John Francis Vater's Hologram
John Francis Vater's Hologram
Mundy Flynn
Mundy Flynn
Ruby is Shot
Ruby is Shot
Saying Goodbye
Saying Goodbye

Quote of the Story

 'We all melt away in the end. But something stays. Maybe the best part. A sad old man once told me, 'What survives of us, is love'.'

The Doctor

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Release Information

FormatTitleRelease Date (UK)Code NumberCover ArtRemarks
The Complete Fourteenth Series Box SetDue: August 2024Photo-montageDVD boxed set containing 7 stories from New Series 14 along with the 2023 Christmas Special "The Church on Ruby Road"
The Complete Fourteenth Series Box SetDue: August 2024Photo-montageBlu-Ray boxed set containing 7 stories from New Series 14 along with the 2023 Christmas Special "The Church on Ruby Road"
The Complete Fourteenth Series Box Set (Limited Edition Steelbook)Due: August 2024Photo-montageLimited Edition Blu-Ray Steelbook boxed set containing 7 stories from New Series 14 along with the 2023 Christmas Special "The Church on Ruby Road"

In Print

No Book Release
Doctor Who Magazine - PreviewIssue 603 (Released: May 2024)

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Photo Gallery

The Doctor and Companion

Ncuti Gatwa
The Fifteenth Doctor


Millie Gibson
Ruby Sunday

On Release

Blu-Ray Steelbook Cover
Blu-Ray Steelbook Cover



Doctor Who Magazine - Preview: Issue 603
Doctor Who Magazine - Preview: Issue 603

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