The Stolen Earth (TV story)

The Stolen Earth was the twelfth episode of series 4 of the revived series of Doctor Who. The episode marks the first television appearance of Davros since the 1988 story Remembrance of the Daleks, and the acknowledgement of the severed hand he lost in Revelation of the Daleks with the advent of a mechanical replacement. The traumatic result of Dalek Caan's emergency escape in Evolution of the Daleks is revealed as well.

It also marked the return of several past associates and companions of the Doctor, including Sarah Jane Smith. Martha Jones, Jack Harkness, Harriet Jones and Rose Tyler. It was the first on-screen appearance of characters introduced in one of the spin-off series, Ianto Jones, Gwen Cooper, Mr Smith, and Luke Smith. The episode also featured the death of Harriet Jones and the loss of the Valiant in ill-fated meetings with the Daleks.

Once again, it showed the legacy that the Doctor leaves behind on Earth, with many of his ex-companions and allies playing a very important part in saving the world.

This episode's cliffhanger, which featured the Tenth Doctor beginning a regeneration, caused much commotion within the circles of Doctor Who enthusiasts, who were taken by surprise. No announcement was made regarding actor David Tennant's departure, which triggered a phenomenal influx of viewers during the Series 4 finale, TV: Journey's End, in anticipation of a new incarnation of the Doctor and new respective actor. However, this flurry of suspense would be dispelled with the outcome of the finale.

Synopsis
When Earth and twenty-six other planets are stolen and taken to the Medusa Cascade and the Doctor nowhere in sight, it's up to the combined forces of UNIT, Torchwood, Sarah Jane and Rose to fight off the thieves, who only have one thing to say to the resistance: "EX-TER-MIN-ATE!".

Plot
Having seen the signs, the Tenth Doctor and Donna return to Earth to find everything in order. The Doctor asks a milkman what day it is — it is Saturday. Donna presses the Doctor for an explanation of Rose's unexpected reappearance, and the Doctor explains that, if Rose can cross from her parallel world to Donna's parallel world, then the walls of reality are breaking down. Still, with Earth apparently safe for now, they return to theTARDIS and prepare to stop the walls breaking. The TARDIS rumbles with an apparent earthquake. The Doctor and Donna rush to the doors and fling them open to find they are hanging in space. The Doctor checks the readings. They have not moved, but the Earth has gone missing. It has been stolen — but by whom?

At the UNIT New York Base, Dr Martha Jones regains consciousness after an earthquake to find UNIT in chaos and its personnel panicking. One horrified colleague tells Martha to look at the sky.

In Torchwood Three, Captain Jack Harkness guesses that the Rift may have been responsible for the brief but violent earthquake that has just devastated the Hub. After making sure that the other members of Torchwood Three — Gwen Cooper and Ianto Jones — are all right, Jack heads outside to survey the damage. Presuming it to be a minor event in the grand scheme of things, Ianto and Gwen look at the computers. Ianto realises that, whatever the problem is, "It's a bit bigger than South Wales".

At 13 Bannerman Road, Ealing, London, Sarah Jane Smith and her son Luke comment on the earthquake — and wonder why it is now dark outside, since it was only 8 a.m. when the quake struck. Sarah Jane asks her alien supercomputer Mr Smith for an explanation. Mr Smith says that she should look outside because she will find the visual evidence more conclusive than his theoretical datastreams. They approach the nearest window and look outside.

In Chiswick, London, Donna's mother Sylvia and grandfather Wilf are not sure what has caused the earthquake, but Wilf is positive it's aliens again. As they step outside their home, Sylvia looks at the sky in horror.

On the street in London where the TARDIS had been parked, the milkman turns and sees Rose Tyler materialise in a flash of white light, carrying a large futuristic gun. She looks up. Alone of the Doctor's friends, she is not surprised. Arming her gun, she declares, "All right, now we're in trouble. And it's only just beginning..."

The familiar sky is gone. The sun is gone. The constellations have been replaced with strange new ones. Twenty-six new planets have appeared in the sky...

Aboard the TARDIS, Donna demands to know if her family is dead. The Doctor does not know. He decides they need help, and he sets course for the Shadow Proclamation.

At Sarah Jane's house, Mr Smith picks up readings of a fleet of two hundred spaceships apparently headed towards Earth. At UNIT, American UNIT leader General Sanchez enters and tells all soldiers and staff that UNIT command Geneva has declared a Code Red Emergency. Martha tells him that she has tried to phone the Doctor, but the signal is dead. The number calls anywhere in the universe, but the signal is being blocked by some unknown force. Sanchez notes that they will likely find out soon: the fleet is coming into orbit...

Martha calls Jack, who says that he hasn't heard from the Doctor either. Gwen calls her husband, Rhys, and tells him to stay indoors and call her mother. Meanwhile, Rose is walking along the streets of London. She threatens a pair of looters with her gun (who promptly scarper) and looks at a computer screen in the electronics shop they were robbing. It shows a readout of the alien ships.

At Torchwood Three, the team see the spaceships. Mr Smith tells Sarah Jane that the ships have a message for the human race, and puts it through. It consists of a single repeated word: "Exterminate". The message is heard on all frequencies, including UNIT, the speakers at Torchwood Three and at Sarah Jane's attic. Jack and Sarah react with horror as they realise the enemy is the Daleks. Jack says, "I'm sorry, We're dead," while kissing Ianto and Gwen. Sarah Jane hugs Luke, crying, "You're so young."

Rose hears the message and heads outside to see a massive Dalek spaceship flying over London, destroying everything in its path. Martha looks outside to see Dalek spaceships flying everywhere, destroying New York. Aboard a massive spaceship at the heart of the cluster of planets, the Daleks finalise their plans. The Supreme Dalek, a red Dalek with extra panels, declares that the Crucible will soon be complete and "We have waited long for this ultimate destiny. Now the Daleks are the masters of Earth!", a chant the Daleks eagerly take up.

Far across the universe, on board the TARDIS and unaware of the unfolding destruction on Earth, the Doctor and Donna arrive at the Shadow Proclamation. They are greeted at gunpoint by its rhino-headed guards, the Judoon, but the Doctor convinces them they mean no harm and need help. A female member of the Proclamation tells the Doctor that the situation is worse than he suspects — not one but twenty-four planets have been stolen. Donna asks about Pyrovillia, but the Judoon captain tells her that Pyrovillia is a cold case; it disappeared over two thousand years ago. Donna asks about the Adipose Breeding Planet and the Doctor realises that planets are being snatched out of time as well as space. The Doctor heads over to the computer and shifts the display of the missing planets into 3D. He adds Adipose 3, Pyrovillia, and the lost moon of Poosh, which all vanished in the past. The model rearranges itself into a perfect balance, fitting together "like pieces of an engine". Back on Earth, the Daleks attack and bring down the Valiant. Jack, Gwen and Ianto try to find a way to stop them, but their efforts are futile. Daleks are landing in Japan, Africa and other countries across the world. Back in Manhattan, the UNIT base is attacked by Daleks. Jack tells Martha to get out of there, but she does not listen. General Sanchez declares that Project Indigo has been activated. He leads Martha and another UNIT soldier to the vault where Project Indigo is being kept and he orders Martha to wear it (it is some kind of suit). As Jack protests for Martha not to use it, that it is too dangerous, General Sanchez orders Martha to do it. He hands her something called "the Osterhagen Key". Martha, understanding what the device is, is horrified and refuses to take it, but General Sanchez orders her to for the sake of humanity. Martha activates Project Indigo as Jack rages. She disappears as the Daleks break in and exterminate the others.

Inside Torchwood, Jack tells Gwen and Ianto that Project Indigo is a teleport device reverse-engineered from the teleport pod salvaged from the Sontarans — but they have no coordinates or stabilisation. When Gwen asks where Martha is, an upset Jack says she has been "scattered into atoms. Martha is down."

On board the Dalek station, the Supreme Dalek orders the Daleks to prepare landings and bring the humans to "the Crucible". He receives a call from the control room, asking about news. The Supreme Dalek declares Earth has been subjugated. The speaker is a sinister figure, with the bottom half of a Dalek but his top half hidden in shadow, with a blue light on what seems to be his head. He is really asking for news of the Doctor. The Supreme Dalek replies that there are no reports of the Doctor and that they are beyond his reach. The figure is fascinated by the Dalek's tone of what seems to be triumph and warns him about his pride. The Supreme Dalek believes the Doctor cannot stop them. The figure replies, "And yet, Dalek Caan is uneasy." A light switches on to show a Dalek with its shell opened to reveal the creature inside, its top half destroyed — it is Dalek Caan, the last of the Cult of Skaro, who had fled 1930s New York in a temporal shift after being defeated by the Doctor. The Supreme Dalek protests, "The abomination is insane!" The figure demands that the Dalek show respect; after all, without Dalek Caan Earth could never be conquered. Also, everything Caan says comes true. Caan says, "He is coming. The three-fold man, he dances in the lonely places...oh, creator of us all...the Doctor is coming!" then bursts into insane laughter.

Back at the Shadow Proclamation's space station, Donna is sitting on the stairs, waiting for the Doctor to work out what has happened. A member of the Shadow Architect's race comes over and gives Donna some water. She somehow knows that there was something on Donna's back and tells her there is a loss still to come. The Doctor asks Donna if anything strange was happening on Earth. Donna reminds him about the bees disappearing. The Doctor realises that this is a clue. Donna tells him some people thought it was pollution or global warming, but the Doctor tells her that in fact the bees were returning home, to the planet Melissa Majoria: the Tandocca Scale. They realise that if they follow the trail they can find the Earth. The Shadow Architect stops them, saying, "The planets were taken with hostile intent. We are declaring war, Doctor, right across the universe and you will lead us into battle!" The Doctor looks stunned, then replies, "Right, 'course I will. I'll just go get you a key." He closes the door and the TARDIS dematerialises, to the Shadow Architect's fury.

Back on Earth, the Daleks have enslaved London and are ordering all humans to leave their homes. Wilf and Sylvia watch. When a man and his children defy them and stay at home, the Daleks brutally incinerate the house, leaving no survivors. Wilf and Sylvia run onto the street and are confronted by a Dalek. Wilf grabs a paintball gun and shoots the Dalek in the eye, but the Dalek melts the paint away. The Dalek prepares to exterminate them, but then explodes. Behind stands Rose, who has shot it with her gun. She asks if they are Donna's family, and when they reply yes, she tells them she needs them. Wilf reveals he has tried calling Donna, but there is no reply. The last time Donna phoned was from the planet Midnight, made of diamonds. Sylvia thinks this is ridiculous, but Wilf tells her she cannot start denying things now. Rose tells them that they are her last hope to find the Doctor.

Meanwhile, the TARDIS stops in the Medusa Cascade. The Doctor tells Donna he came here when he was just a kid (ninety years old) and that it is the centre of a rift in time and space. Donna asks about the twenty-seven planets. The Doctor tells her that they are nowhere. Donna asks what they are to do, but the Doctor does not reply. Despite Donna's pleas, the Doctor is about to give up...

On Earth, Sarah Jane and Captain Jack have given up. At the Nobles' house, the laptop suddenly switches itself on and a voice comes through. Sarah and Torchwood hear it too. Jack tells Gwen to leave it, but the woman speaking shames him and demands that he stand to attention. She identifies herself as Harriet Jones, former prime minister. Rose tries to talk to Harriet, but she can't hear her — Wilf and Sylvia don't have a webcam (because "they're naughty"). Harriet also makes contact with Sarah and decides they should be able to talk to each other. There are four contacts: Harriet, Sarah and Torchwood, but the fourth contact is having trouble getting through. Rose assumes this is her, but is surprised when Martha appears on screen, protesting, "Who's she?". Martha reveals that Project Indigo brought her home to her mother, possibly tapping into her mind to determine where she really wanted to go. Harriet introduces Torchwood to Sarah. Jack has been following Sarah's work, telling her, "Nice job with the Slitheen." Sarah has been staying away from Torchwood — "Too many guns" — and Jack responds by telling her, "Looking good, ma'am." Harriet is unimpressed by Jack's incorrigible flirting and explains that this is the subwave network — a sentient computer programme obtained from the Mr Copper Foundation to contact anyone and everyone who can contact the Doctor. Harriet wants them to form the Doctor's Secret Army. Sarah wonders why Harriet is doing this, given that the Doctor deposed her; Harriet has wondered ever since that time if she was wrong.

Regardless, she stands by her actions to this day. She always felt that there would be a day when Earth would be threatened and the Doctor would not appear. She told him so and he did not listen: now it has happened. Torchwood realise they can transmit to the Doctor using all the power of the Rift. Luke points out that Mr Smith can tap into the global telecommunications network, forcing every phone across the globe to call the same number at the same time; Jack is impressed. Ianto appears beside Jack and theorises that as soon as transmitting begins, the subwave network will become visible to the Daleks. Harriet understands that the signal will be traced back to her, but she declares her life does not matter — not if it saves the world. She tells Jack to tell the Doctor a few things from her, concluding, "He chose his companions well." Martha sends them all the Doctor's phone number; Rose decides to call the Doctor herself.

The transmitting starts. Rose, Sylvia and Wilf start to call the Doctor. Mr Smith and the equipment at Torchwood are pushed beyond their limits. Suddenly, transmitting slows. The Daleks detect the subwave network, and the Supreme Dalek orders that the culprit be exterminated. The figure in the control room contacts him again, telling him, "I warned you, Supreme One. Just as Dalek Caan foretold, the Children of Time are moving against us. But everything is falling into place..." Gwen tells Harriet they have found her, but Harriet keeps working. She sends control to Torchwood, just as the Daleks arrive in her home. When the Daleks tell her they know her after she introduces herself yet again, Harriet says, "Oh, you know nothing of any human. And that will be your downfall." With this, she is exterminated.

On board the TARDIS, as the Doctor and Donna sit despondent, the phone Martha gave him starts ringing. Although there is no voice on the other end, the Doctor picks up the signal and locks onto it. The TARDIS travels through time, overloading. The twenty-seven planets come into view and the Doctor realises that they were all one second out of sync with the universe — the perfect hiding place. He picks up the subwave network and his companions appear onscreen. The Doctor introduces Donna to all of them, but is disappointed that Rose is not visible.

On board the Crucible, Caan says, "He is here...the Dark Lord is coming..." The figure demands access to the subwave network...

Suddenly, all the contacts vanish off-screen. Donna thinks they are losing contact, but the Doctor realises there is another contact coming through. He thinks it is Rose, but it is a different voice, one that Sarah Jane and he recognize in horror: "Your voice is different and yet, its arrogance is unchanged..." The figure is revealed as Davros. He says, "Welcome to my new empire, Doctor. It is only fitting that you should witness the resurrection and the triumph of Davros, lord and creator of the Dalek race." The Doctor protests that Davros was destroyed in the very first year of the Time War; his command ship flew into the jaws of the Nightmare Child at the Gates of Elysium, even though he tried to save Davros. Davros says, "But it took one stronger than you — Dalek Caan himself." Caan says, "I flew into the wild, and the fire; I danced and died a thousand times." Davros tells the Doctor that his emergency temporal shift from 1930 took him back into the Time War. The Doctor protests that the war is time-locked. Yet Caan broke the barriers and rescued Davros — albeit at the cost of his mind. The Doctor realises Davros has created a new race of Daleks. Davros says, "I gave myself to them — quite literally: each one grown from a cell of my own body." He reveals that parts of his torso have been replaced by metal — much of his ribcage is clearly visible. As Davros says, "New Daleks...true Daleks. I have my children, Doctor. What do you have now?" the Doctor says one thing: "Bye!" He cuts transmission with Davros and sets the TARDIS for Earth. The Supreme Dalek orders that the Daleks locate the TARDIS and the Doctor, but Davros points out that the Time Lord is going to Earth, where his companions are. Caan says, "Death is coming. I can see it! Everlasting death for the most faithful companion..." Suddenly, the Daleks detect that the subwave network has been rebooted and the new location is Torchwood. The Supreme Dalek orders Torchwood exterminated.

On Earth, Jack contacts Martha by phone and asks what the two oscillating digits on the Project Indigo transporter are; they are a 4 and a 9. Jack tells her that those are the teleport base codes, which is all Jack needs to reactivate his vortex manipulator's teleportation ability. Jack grabs the re-powered defabricator and promises Gwen and Ianto that he will come back, then vanishes.

Sarah heads off to find the Doctor in her car, as Mr Smith promises to protect Luke. Rose contacts the parallel Torchwood and has them lock her onto the TARDIS, before being teleported away.

The TARDIS lands in a trashed and deserted street. The Doctor asks Donna what Rose said in the parallel Earth and Donna replies with a smile, "Why don't you ask her yourself?" The Doctor turns around and sees Rose standing down the street. They run towards each other, absolutely delighted. As they get closer a Dalek appears from behind a van and shoots the Doctor, sending him to the ground. Captain Jack teleports into the street and blasts the Dalek to bits with his defabricator gun. A distraught Rose kneels over the Doctor as he lies on the ground in agony, as Jack and Donna prepare to move him into the TARDIS.

Back in Torchwood Gwen and Ianto pick up machine guns, knowing full well that they won't help, and get ready for battle; Gwen is prepared to go out like the recently deceased Owen and Tosh. A Dalek enters Torchwood and Gwen and Ianto open fire...

Back in the TARDIS the Doctor is in terrible pain. Donna asks if there's anything they can do to help him but Jack tells her to stay away. The Doctor lifts up his hand, which has begun to glow...

Sarah Jane is still in her car, driving down a street until she nearly hits two Daleks on the road. Despite her frantic attempts to apologise, the Daleks prepare to exterminate her...

Back in the TARDIS Jack makes the others back away. When Donna asks what's going on, Rose explains that when the Doctor is dying he can heal himself, but changes in the process. Rose doesn't want the Doctor to change as she has come a long way to find him — but the process has already started and can't be stopped...

In Torchwood Three, Gwen Cooper and Ianto Jones aim their weapons and pull the safety catches, as the Dalek says for a third and final time, "Exterminate..."

The Doctor gets to his feet. Glowing brighter and brighter by the second, he stretches his arms out as his body explodes into golden energy and begins to regenerate...

Cast

 * The Doctor - David Tennant
 * Donna Noble - Catherine Tate
 * Rose Tyler - Billie Piper
 * Martha Jones - Freema Agyeman
 * Captain Jack Harkness - John Barrowman
 * Sarah Jane Smith - Elisabeth Sladen
 * Davros - Julian Bleach
 * Wilfred Mott - Bernard Cribbins
 * Sylvia Noble - Jacqueline King
 * Gwen Cooper - Eve Myles
 * Ianto Jones - Gareth David-Lloyd
 * Luke Smith - Tommy Knight
 * Harriet Jones - Penelope Wilton
 * Francine Jones - Adjoa Andoh
 * Mr Smith - Alexander Armstrong
 * General Sanchez - Michael Brandon
 * Shadow Architect - Kelly Hunter
 * Albino Servant - Amy Beth Hayes
 * Suzanne - Andrea Harris
 * Paul O'Grady - Himself
 * Richard Dawkins - Himself
 * Trinity Wells - Lachele Carl
 * Drunk Man - Marcus Cunningham
 * Newsreader - Jason Mohammad
 * Scared Man - Gary Miller
 * Dalek operators - Barnaby Edwards, Nick Pegg, David Hankinson, Anthony Spargo
 * Judoon captain - Paul Kasey
 * Voice of the Daleks - Nicholas Briggs

Earth businesses

 * Rose examines the Daleks arrival on Earth via a laptop in the shop Megabyte City.

Daleks

 * Wilf uses a paintball gun gun as a weapon against the Daleks by shooting paintballs at their eye stalks, hoping to blind them; it proves to be completely ineffective.
 * Caan referred to the Doctor as "the Dark Lord". He is also known to the Daleks as the Ka Faraq Gatri (or "Destroyer of Worlds") and "the Oncoming Storm".
 * The new Daleks are said to be Davros's "children" as they have been grown from his own cells.
 * The Daleks' weaponry has been updated to include a "maximum extermination" setting, capable of destroying a house if three Daleks fire at the same target.
 * The Vault Daleks lack the normal "plunger" attatchment and now have a claw-like arm.

The Doctor

 * The Doctor first went to the Medusa Cascade when he was "just a kid" at the age of ninety.
 * The Doctor says he likes Saturdays.

Last Great Time War

 * The Doctor says that Davros died in the early years of the Time War, when Davros's ship flew into the "jaws of the Nightmare Child".
 * It's revealed that Davros fought in the Time War and the Doctor tried to save his life.

Planets

 * Only a few of the missing planets are mentioned by name: Callufrax Minor, Woman Wept, Clom, Pyrovillia, Adipose 3, the Lost Moon of Poosh, Jahoo, Shallacatop, and Earth. Pyrovillia was the homeworld of the Pyroviles, Adipose 3 the breeding world of the Adipose, whilst Dee Dee Blasco became Professor Hobbes' research assistant after writing a paper about the disappearance of the Lost Moon of Poosh.
 * Callufrax Minor seems to be a reference to Calufrax, the disguised Second Segment of the Key to Time ("The Pirate Planet"), both by name and because the planet was compressed to golf-ball size by Zanak.

Technology

 * Reference is made to "Osterhagen keys". The keys activate a chain of twenty-five nuclear warheads placed in strategic locations beneath the Earth's crust which, on detonation, would rip the Earth apart. The Key is only to be used if "the suffering of the human race is so great, so without hope, that it becomes the final option". All holders of the keys appear to be members of UNIT. Significantly, while Harriet Jones is also aware of it and forbids its use, Jack Harkness and Torchwood are not.
 * Harriet Jones uses the subwave network to put the Doctor's "secret army" in contact with each other. It utilises sub-wave communication developed by the Mr Copper Foundation. Donna compares it to an interspace Facebook.
 * A dimension cannon is used to travel between different parallel universes.

Story notes

 * This episode is the seven hundred and fiftieth broadcast episode of Doctor Who.
 * This episode was the last of Series 4 to have its title revealed.
 * This is the fourth time that the Daleks have returned with a leader in a finale. In TV: The Evil of the Daleks they returned led by their emperor; in the 2005 finale, The Parting of the Ways, the Daleks were led by the Dalek Emperor; and in the 2006 finale, Doomsday, Dalek Sec led the Cult of Skaro. The two-part Dalek story in 2007 was shown as the fourth and fifth episodes of the series (Daleks in Manhattan and Evolution of the Daleks).
 * There was originally a scene where a Dalek Saucer landed at Westminister and one in which the Daleks exterminated the Prime Minister, Aubrey Fairchild, before the Dalek invasion force emerged from the saucer. An unseen character in The Next Doctor was named Aubrey Fairchild.
 * The "To Be Continued" before the end credits is different from the others previously used. There is also no sneak peek of the next episode, probably not to reveal what has happened to the Doctor after his regeneration. It is the only the second episode (after Rise of the Cybermen) that has used this method of continuation.
 * When Harriet Jones contacts Captain Jack, Martha Jones and Sarah Jane Smith, the contact tone is the same tone used by the Master to control the populace under the Archangel network.
 * For the first time, the opening credits incorporate not two or three names, but six, adding Freema Agyeman, John Barrowman and Elisabeth Sladen to the Tennant, Tate and Piper credits of the previous week. The typeface used for these credits is slightly different than that usually used. In addition, several "overflow" cast credits are featured over the first scene after the opening sequence, a first for the series (Penelope Wilton, Adjoa Andoh, Eve Myles and Gareth David-Lloyd). Although the appearances of Harriet Jones and Francine Jones are clearly intended to be surprises, the surprise is weakened for anyone who recognised the names of Wilton and Andoh in these opening credits. Despite their major roles in this episode, neither Bernard Cribbins nor Jacqueline King received similar credits.
 * Scientist and author Richard Dawkins has a cameo as himself. Dawkins is married to Lalla Ward, the actress who portrayed Romana II. The two were introduced by Douglas Adams, who met Ward in his capacity as the show's script editor during the time Ward's ex-husband, Tom Baker, played the Fourth Doctor.
 * The claws of the Daleks in Crucible are very similar to ones in the Dr. Who and the Daleks movie, but with eight fingers instead of two.
 * The clicking sound when the Time Beetle from Turn Left was mentioned occurred when Donna was offered water at the Shadow Proclamation, accompanied by the same words used when the Time Beetle was "seen" by somebody else, "There's something on your back!"
 * The original Sci-Fi channel broadcast in the United States cut some scenes to fit the different commercial times.
 * The differences between the child-friendly Sarah Jane Adventures and the very adult-oriented Torchwood are reflected in the onscreen conference. Sarah Jane mentions that she tries to steer away from Torchwood because they have "too many guns", nodding to Luke as she does so. Despite this, Jack cannot resist flirting with her and she seems to appreciate his compliment.
 * The concept of the bees leaving the earth and heading to another planet as it seems the end is near strongly reflects the dolphins from The Hitchhiker's Guide to the Galaxy, who also left the planet right before its impending doom. Though most likely a coincidence, it should be noted that Douglas Adams, who wrote Hitchhiker's Guide, was a writer and script editor for Doctor Who.
 * Another reference to The Hitchhikers Guide to the Galaxy occurs when a Dalek near the start of the episode shouts, "Resistance is useless". This line was often used by Vogons (an alien in THGTTG) when they captured Arthur Dent and Ford Prefect.
 * When the TARDIS is hurtling toward the headquarters of the Shadow Proclamation, a scene is reused from TV: The Parting of the Ways, where the Ninth Doctor flew the TARDIS into battle against a Dalek fleet, which bombarded it with torpedoes. Coincidentally, this episode is also centred around a major Dalek conflict.
 * In the scene in the Shadow Proclamation, it was originally planned to show many more aliens old and new including:
 * Raxacoricofallapatorians with a child. This child was originally conceived as Margaret following her regression to an egg (TV: Boom Town)
 * Baby Adipose and very big adult one (imagined by Russell T Davies as being about fifteen feet tall)
 * Scholars of the University of Rago Rago 56 Rago or members of the same species
 * Krillitane
 * Vespiform
 * Hath
 * Gelth-like species
 * Cybermen
 * Sycorax
 * Alonso Frame working for the Shadow Proclamation as a Shadow Soldier
 * Isolus
 * Graske
 * Kroton
 * Hoix
 * Chelonian-like species
 * Two-headed race (Aplans?)
 * While this scene was not transmitted in this episode, it could have been scaled down to become the space-bar scene in the final scenes of the second part of The End of Time. 


 * When Sarah Jane summons Mr Smith, she complains about the musical fanfare that accompanies the computer's activation; this is the culmination of a recurring gag in The Sarah Jane Adventures in which the same fanfare (usually) blares whenever Mr. Smith is activated. This is the first time, however, that it is confirmed the characters actually hear this music.
 * An ongoing question relating to why the Doctor can't or won't go back to the era of the Time War to make things turn out differently is addressed by the Doctor indicating that the war is time-locked; Dalek Caan, having circumvented this barrier, paid for the experience with his sanity.
 * This story was chosen by BBC America to represent the David Tennant era during their 50th anniversary programming. Edited into an omnibus format with Journey's End, it was aired by BBCA on 27 October 2013, after the debut of their homegrown special called The Doctors Revisited - The Tenth Doctor.

Ratings
to be added

Myths and rumours

 * The presence of Davros in this episode had been rumoured for a long time before broadcast. An associated rumour suggested that the episode would reveal that Donna was actually Davros in disguise or Caan mutated himself into Davros. See this section in Journey's End for additional rumours related to Donna.
 * It was also rumoured on the fan boards that Patrick Stewart or Ben Kingsley might have been cast as Davros. The speculation surrounding Stewart followed media reports of his interest in appearing in Doctor Who after it was announced that he and Tennant would perform a season of Shakespeare together in 2008. Ultimately, Julian Bleach was revealed to be playing the character.
 * The cliffhanger regeneration ending sparked a week's worth of widespread speculation as to whether David Tennant was in fact about to hand the role over to another actor, despite reports that he was to at least appear in the upcoming Christmas special. The rumours, of course, were put to bed upon the cliffhanger's resolution.
 * It was also rumoured that there would be a massive fight between the Judoon and the Daleks that would decide the fate of planet Earth. This was proven false.
 * It has been rumoured, but never confirmed, that Russell T Davies was originally planning to bring back Clive Swift as Mr. Copper from Voyage of the Damned but changed his mind after Swift's interview for DWM 391 in which he refused to answer some questions and insulted the interviewer (Benjamin Cook), the franchise and the fandom in general before terminating the interview altogether.

Filming locations

 * Cardiff
 * Pontypridd

Production errors

 * In the scene just before Martha teleports with Project Indigo, her earpiece disappears, then reappears when she takes it off.
 * When the Daleks discover the location of the subwave network has been moved to Torchwood, the Dalek who announces it to the Supreme Dalek only has its eyestalk light turned on just as he says Torchwood, which is the last word of the line.

Continuity

 * This episode marks the first on-screen appearance of the Shadow Proclamation, first mentioned in TV: Rose.
 * The Medusa Cascade was mentioned in TV: Last of the Time Lords and TV: The Fires of Pompeii.
 * The Doctor refers to the lost moon of Poosh (TV: Midnight).
 * The Valiant last appeared in TV: The Poison Sky to help UNIT with attacking the ATMOS factory and, before that, in TV: The Sound of Drums. In this episode, it is seen being swarmed (and most likely destroyed) by a huge group of Daleks using 'maximum extermination'.
 * The Doctor deposed Harriet Jones in TV: The Christmas Invasion.
 * The gun that Captain Jack used to kill the Dalek with appears to be the same gun he used in TV: The Parting of the Ways.
 * The Doctor previously disabled the teleportation function of Captain Jack's Time Agency wrist strap in TV: Last of the Time Lords; Jack regains the correct digits to reactivate it in this episode.
 * Gwen states to Ianto, after handing him a firearm during the Dalek invasion of Torchwood 3, that she intends to "go out fighting" like Owen Harper and Toshiko Sato. (TV: Exit Wounds)
 * The Doctor mentions a previous attempt to move the Earth "a long time ago". In TV: The Dalek Invasion of Earth, the Daleks tried to place a drive system into the centre of the Earth so that they could pilot the planet. In TV}}: [[The Trial of a Time Lord, the Time Lords successfully moved the Earth, causing it to become known as Ravolox. The Cybermen also successfully moved and piloted Earth's twin planet, Mondas. (TV: The Tenth Planet)
 * Sarah Jane Smith, Rose, Jackie, Mickey, Jack, and Martha have all encountered the Daleks before. (TV: Genesis of The Daleks, Dalek et al)
 * Donna is told that she had something on her back. She was first told she had something on her back in TV: The Fires of Pompeii and it was a major element of the preceding episode, TV: Turn Left.
 * This is the second on-screen appearance of the Judoon, the first being TV: Smith and Jones. They also appear in PROSE: Revenge of the Judoon.
 * The Daleks proclamation that "The Daleks are the masters of Earth!" was previously said in TV: The Dalek Invasion of Earth, where they also issued the command for "the males, the females and the descendants" to come into the street and surrender to them.
 * The Doctor calls out, "Bye!" to Davros in a similar fashion that the Fourth Doctor bade him farewell in TV: Destiny of the Daleks. The Master also says something similar in TV: Utopia, whilst stealing the TARDIS, as a rather childish "Bye-Bye!"
 * Jack refers to Sarah Jane's encounters with the Slitheen. (TV: Revenge of the Slitheen and/or TV: The Lost Boy)
 * The Doctor's TARDIS has reverted to its original appearance and is no longer covered with the words "Bad Wolf" as at the end of TV: Turn Left.
 * Mr. Smith using every phone on Earth to call the Doctor is similar to everyone saying, "Doctor" in TV: Last of the Time Lords, where mobile phones also played an integral role as the transmitters of the Archangel Signal.
 * In The Parting of the Ways, the Emperor of the Daleks refers to Rose as 'the Abomination', and in this episode the Dalek Supreme used the same nickname for Dalek Caan. This is also the name given to the Special Weapons Dalek in the novelization of Remembrance of the Daleks. This seems to be a popular name (or insult) for things that that the Daleks hate or fear.
 * The Doctor and Rose are reunited near a church, echoing the setting of TV: Father's Day in which Rose's father is killed by an oncoming car and dies in the street. In this instance, Rose witnesses the Doctor being mortally wounded by a Dalek, and cradles him as he lies dying in the street.
 * On screen, the Doctor was last shown meeting Davros in TV: Remembrance of the Daleks. This episode establishes that they had at least one more encounter, during the Time War. Davros acknowledges that the Doctor has changed again since their last meeting.
 * The Third Doctor was also shot by a Dalek. On that occasion, his legs were temporarily paralysed. (TV: Planet of the Daleks)
 * Upon answering the phone to Martha the first time, Jack says, "Martha Jones, voice of a nightingale" — the same words he used in TV: Reset.
 * Davros now has a mechanical, slightly claw-like hand. His flesh-and-blood hand was shot off in TV: Revelation of the Daleks.
 * In AUDIO: The Juggernauts, the self-destruct mechanism of Davros' life-support chair explodes, leaving him as presumably nothing but a head. In TV: Remembrance of the Daleks, only his head is visible as he is inside an Emperor Dalek casing. Here, his body is how it was in TV: Revelation of the Daleks, and his torso is clearly seen.
 * In AUDIO: Terror Firma, the "Emperor" personality in Davros becomes dominant and he becomes, mentally, an Emperor Dalek. Here, he is clearly Davros again.
 * Wilf uses a paintball gun as a weapon against the Daleks by shooting paintballs at their eye stalks. This technique was first used in the Daleks' debut in the series in the 1964 episode "The Escape".
 * In previous encounters (eg, The Daleks, Planet of the Daleks, Resurrection of the Daleks) in which a Dalek eye would be shot, or covered, the Dalek would cry hysterically, "My vision is impaired! My vision is impaired!" When Wilfred attempts to exploit this weakness here and shoots a Dalek in the eye with his paint gun, it says, "My vision is not impaired".
 * Harriet Jones has yet again introduced herself by flashing her identity card earning her the response of "Yes, I/we know who you are", even from the Daleks dispatched to her location to exterminate her. (TV: The Christmas Invasion)
 * Luke's comment about spatial transference echoes a similar statement made by Grace Holloway when she displays unexpected knowledge of physical theory in the 1996 Doctor Who TV movie. (TV: Doctor Who)
 * General Sanchez is heard saying, "Ladies and gentlemen, we are at war." The same phrase was spoken by Jack Harkness when facing the Daleks on the Game Station. (TV: The Parting of the Ways)
 * Woman Wept was mentioned by Rose when talking to Mickey of the planets she had visited. It had experienced an unknown sudden freezing of its oceans, which at the time was unexplained. (TV: Boom Town)
 * The missing planet Callufrax Minor may be a reference to Calufrax, the miniaturised planet and Key to Time segment of The Pirate Planet.
 * When the sub-wave network patches through to Rose at Donna Noble's home, the ring tone matches the rhythm of the drums that the Master spoke of in The Sound of Drums and Last of the Time Lords.

Home video releases

 * This story was released in the Series 4 DVD box set in November 2008 along with the rest of the series.
 * It was released as Series 4 Volume 4 in a vanilla edition with Turn Left and Journey's End.