Journey's End (TV story)

"For this is my ultimate victory, Doctor! The destruction of reality itself!!"

- Davros

This is the 13th and final episode of Series 4 and featured 6 companions of the Doctor. It is a continued on a cliffhanger from Episode 12. It holds the distinction of being the highest-rated episode in the history of the Doctor Who franchise.

Synopsis
The entire universe is in danger as the Daleks  activate their master plan to destroy reality itself. The Doctor is helpless, and even the  TARDIS  faces destruction. The only hope lies with the Doctor's secret army of companions– but as they join forces to battle Davros himself, the prophecy declares that  one of them will die.

Plot
The Doctor is regenerating inside the TARDIS while Donna Noble, Captain Jack Harkness and Rose Tyler watch in horror. However, the Doctor transfers his regenerative energy into the container which carries his severed hand. He has healed himself, but chosen not to change his appearance. The TARDIS is transported by the Daleks to the Crucible and rendered powerless. The Doctor, Jack, and Rose leave it, but Donna is distracted because she is hearing the sound of a heartbeat and while looking back, the TARDIS door slams closed. Before the Doctor can free her, the Daleks dump the TARDIS into a waste chute where it will be destroyed in the centre-core of the Crucible. As the TARDIS interior explodes around her, Donna collapses near the severed hand, she hears the heartbeat again and while touching the container energy flows between it and her. The hand bursts out of the container, and forms as a new Doctor, although this Doctor has only one heart and has picked up some of Donna's mannerisms. With his help, the TARDIS escapes destruction and gives the new Doctor and Donna time to come up with a plan.

In Torchwood Three, Gwen Cooper and Ianto Jones find themselves safely in a time lock created by Toshiko Sato, preventing the Dalek from entering but also preventing them leaving. Sarah Jane Smith is saved from two Daleks by Mickey Smith and Jackie Tyler, but in order to follow the Doctor, they lay down their guns and allow themselves to be captured, taken to the Crucible. Martha Jones says her goodbyes to her mother and makes for an abandoned castle in Germany where one of five Osterhagen stations is hidden, and waits for contact from the other bases.

Aboard the Crucible, Jack creates a distraction by shooting the Supreme Dalek with his revolver, but is exterminated by the Daleks; as the Doctor and Rose are taken to the Vault where Davros is held, Jack's immortality allows him to escape. With the Doctor and Rose contained, Davros explains that the 27 planets form an energy pattern that is then amplified into a "reality bomb", able to break apart the forces holding everything together. Mickey, Jackie, and Sarah Jane escape a test chamber where this effect is shown to the Doctor just in time. Jack finds his way to the three, and with a locket from Sarah Jane, creates a device that will implode the Crucible. Meanwhile, Martha makes contact with two other bases in China and Liberia. The Chinese counterpart wants to get it over and done with, but Martha, knowing the Doctor, first broadcasts a signal to the Crucible to give them (probably both Earth and the Daleks) a second chance, promising to use the Osterhagen key to detonate 25 nuclear warheads under the Earth's crust to destroy it and disable the reality bomb. However, the Daleks manage to lock onto their positions and beam Martha, Jack, Mickey, Jackie, and Sarah Jane, with the Transmat to the Vault where the Doctor and Rose are also being held captive. The Daleks prepare to activate the reality bomb that will wipe out all matter in this and every parallel universe through the rifts in the Medusa Cascade, but the new Doctor and Donna arrive in the TARDIS. Both, however, are stunned by shots from Davros. The reality bomb countdown reaches zero, but nothing happens; Donna has manipulated the controls to disable it. The Doctor recognises that the creation of the new Doctor has had an unintended side effect: Donna is now half Time Lord herself, sharing the Doctor's intellect. Donna and the new Doctor free the others, and with the help of the original Doctor, disable the Daleks and start to send the planets back to their proper time and space. Before Earth can be sent, the machinery is destroyed by the Supreme Dalek, who is then destroyed by Captain Jack. The original Doctor races into the TARDIS to replace the functionality of the broken machine. Realising that Dalek Caan has seen the end of the Dalek race and has been manipulating time to achieve this, the new Doctor (probably not kept back by guilt due to the influence of Donna's personality) uses the remaining machinery to destroy all of the Daleks and their fleet. The rest of the companions flee to the TARDIS, and while the Doctor offers to save Davros, he refuses, calling the Doctor the "Destroyer of Worlds". The Crucible is destroyed.

The Doctor enlists the help of the other companions, making contact with the Torchwood base, and with Luke Smith, Mr. Smith and K-9, help use the TARDIS to return the Earth to its proper place. Sarah Jane says her goodbyes, as well as Jack, Martha, and Mickey, who has decided to stay in this universe. Using a retroactively closing rift, the Doctor returns Rose and Jackie to the alternate dimension and leaves the new Doctor with her, because he is the same Doctor who fell in love with Rose and she with him, the only difference being that he will now grow old with Rose, no longer able to regenerate due to the human influence. The Original Doctor uses the excuse that by destroying the entire Dalek Race, the new Doctor has committed genocide, but if he truly felt that he were dangerous, he never would have left him with Rose. The Doctor simply wanted to give Rose and a part of himself the one adventure he could never have: A full life of love shared with someone until the end.

Rose asks both Doctors the words that the Doctor was unable to say to her when they last parted (DW: Doomsday). The human doctor, having the same memories and feelings as the proper Doctor, whispers into Rose's ear (most likely telling her that he loves her), and they kiss.

Returning to their universe, Donna finds she begins to have trouble thinking; the Doctor explains that the human mind cannot take in the Time Lord mental abilities. To save her, he wipes her mind of all her encounters with the Doctor, returning her home and explaining to her family, Sylvia Noble and Wilfred Mott, that she must never be reminded of her time with the Doctor or else she will die. As Donna recovers consciousness, she shows no interest in the Doctor; he leaves, though Wilfred promises he will look out for the Doctor every night while he looks at the sky. The Doctor then returns to the TARDIS alone....

Cast

 * The Doctor - David Tennant
 * Donna - Catherine Tate
 * Rose - Billie Piper
 * Martha - Freema Agyeman
 * Captain Jack Harkness - John Barrowman
 * Sarah Jane - Elisabeth Sladen
 * Clone Doctor - David Tennant
 * Mickey Smith - Noel Clarke
 * Jackie Tyler - Camille Coduri
 * Luke Smith - Thomas Knight
 * Gwen Cooper - Eve Myles
 * Ianto Jones - Gareth David-Lloyd
 * Wilfred Mott - Bernard Cribbins
 * Sylvia Noble - Jacqueline King
 * Francine Jones - Adjoa Andoh
 * Davros - Julian Bleach
 * Dalek Voice - Nicholas Briggs
 * Mr Smith - Alexander Armstrong
 * K-9 - John Leeson
 * German lady - Valda Aviks
 * Scared Woman - Shobu Kapoor
 * Anna Zhou - Elizabeth Tan
 * Liberian - Michael Price

Production crew

 * Dalek Operators - Barnaby Edwards, Nicholas Pegg, David Hankinson, Anthony Spargo, Gethin Jones

Individuals

 * Those shown in flashback who died for the Doctor are Harriet Jones, Jabe, The Controller, Lynda Moss, Robert MacLeish, Mrs Moore, Colin Skinner, Bridget Sinclair, Ursula Blake (who did not die but was left permanently disfigured and incapacitated), Face of Boe, Chantho, Astrid Peth, Luke Rattigan, Jenny (who is in fact not dead, but the Doctor is unaware of this), River Song and the Hostess.
 * Both Rose and the Doctor recognise the familiar resemblance between Gwen Cooper and Gwyneth (who they encountered in Cardiff in 1869).
 * Rose and Mickey, who previously had an on again, off again relationship, appear to have drifted apart. They do not look at each other, speak to each other, or interact at all, even when they are in the TARDIS together. Mickey does not say goodbye to her (though he does say goodbye to Jackie saying he'll miss her "more than anyone") and he tells the Doctor there's nothing for him in the parallel world, "certainly not Rose".
 * Mickey and Jack's initial dislike of each other appears to have been overcome by both men, possibly due to Mickey's growth into a more mature and capable individual.
 * Just before the Doctor is forced to erase her memory, Donna expresses a desire to meet Charlie Chaplin. This is the second finale in a row to have a character state a desire to meet a famous 20th century personality; previously the Doctor told Martha he wanted to meet Agatha Christie (DW: Last of the Time Lords); Christie subsequently appeared in The Unicorn and the Wasp; it remains to be seen if Donna's reference also serves a foreshadowing. As her mind begins to melt down, Donna also references the American comic strip character Charlie Brown.
 * Like Mickey, Jackie seems to have matured considerably during her stay in the alternate universe. She expertly shoots down a Dalek with a large gun, walks into captivity with little hesitation and expresses sorrow and compassion for a woman she barely met.

Full TARDIS

 * This is the first episode where the TARDIS is fully-staffed with six pilots, and the first time it is noted definitively that it was designed for six, after various mentions about it being made for more than a single Time Lord.

Technology

 * The purpose of the Osterhagen key is revealed in this episode.  Martha's key is one of several required to set off a network of nuclear weapons buried deep beneath the Earth's surface.  If detonated, these weapons would trigger the explosion of the Earth.  Each key must be inserted into a control panel at an "Osterhagen station". There are apparently five around the world, but only three need to be manned with a key to initiate the detonation.  Locations seen on screen are Germany, Liberia, China and an unmanned Argentina.  The "Osterhagen Project"  appears to have been in place for decades, according to the German Woman who supplied food to the guards at the German station.  Given the age of the German Woman, and her claim that she knew of the Osterhagen key when she was in London during her youth, the "Osterhagen Project" likely dates to the days when the Brigadier was in charge of the British arm of UNIT.
 * The technology used to emplace the nuclear weapons at the Earth's crust could therefore be linked to the drilling project featured in DW: Inferno''.


 * The Daleks have access to transmat technology.
 * The TARDIS is captured by the Daleks in what they call a temporal prison but what the Doctor calls a chronon loop.
 * Toshiko Sato installed a time lock around The Hub at Torchwood Three.
 * Sarah Jane uses her sonic lipstick in the same manner as the Doctor's sonic screwdriver. This is the tool's first appearance in the main series.
 * The "three Doctors" send the planets back to their original position through the use of a "magnetron". It is unclear if this is an intentional reference to the magnetrons seen previously in the original series (DW: Day of the Daleks, The Mysterious Planet), or just a general reference to real life magnetrons, used to power microwaves, radar screens and televisions.

Story notes

 * Two major scenes were cut from the episode before broadcast. One was an extra piece of dialogue on Bad Wolf Bay where the Doctor hands his clone a coral-like piece of the TARDIS, telling him to grow his own. When the clone Doctor protests that it takes thousands of years to grow a TARDIS, DoctorDonna provides him with a solution. The second scene was a an alternate ending. After saying goodbye to Wilf, the Doctor returns to the TARDIS, which dematerializes; in the kitchen, Donna hears the sound and there is a brief look of recognition on her face which she dismisses; in the TARDIS, a scanner begins receiving a strange signal, prompting the Doctor to launch into his traditional "What? What? What?" response, after which two Cybus Cybermen suddenly rise up behind him - a cliffhanger. Both scenes were included in the Series 4 DVD set released in November 2008; in his commentary, Davies explains that the cliffhanger ending was dropped in response to comments by a writer with Doctor Who Magazine who stated a cliffhanger was inappropriate after such a sad series of scenes. Unlike most deleted scenes from Series 4, it is not possible to retroactively work the "TARDIS piece" and Cyberman cliffhanger sequences into continuity: the Bad Wolf Bay sequence plays out as one long exchange and no room exists to reinstate the discussion about the TARDIS; and the cliffhanger does not coincide with the opening of The Next Doctor which shows the Doctor not in peril. It is possible, however, for the scene of Donna recognizing the TARDIS sound to be fit into continuity.
 * Had the Cybermen scene been kept, this would have marked the first time since Doomsday that both Daleks and Cybermen had appeared in the same episode, and the first time Cybermen would have appeared in the same episode with Davros.
 * Blue Peter presenter Gethin Jones operates a Dalek in this episode, returning to Doctor Who since his brief appearance as a Cybus Cyberman in The Age of Steel.
 * This was the longest series finale at 65 minutes long, longer even than most of the Christmas specials, except for Voyage of the Damned, which was 71 minutes.
 * Dalek Caan refers to the Doctor as a 'threefold man'. The meaning becomes clear in this episode with both the copy of the Doctor and 'Doctor-Donna'.
 * Once again, as with the previous episode, the opening credits are augmented to include six names, with several overflow acting credits displayed after the opening sequence.
 * This episode marks the first series finale to show a preview of the upcoming Christmas [Special] (2008). After the credits the Cybermen are said to return in the episode. However the episode is unique for being the only series finale in the Russell T Davies era which doesn't end on a cliffhanger (but see above).
 * Graeme Harper's penchant for including a distorted image of a main character is present in this story.  Though not included in  every single story he's directed for BBC Wales, it's seen often enough to be considered something of a directorial "signature".  Similar distortion is achieved through the use of  magnifying glasses in Army of Ghosts, The Unicorn and the Wasp, and Utopia,  and with mirrors in Turn Left.   This time, it's Mickey, Jackie and Sarah Jane that get "the Harper treatment" under a curved window.
 * Davros named the Doctor 'The Destroyer of Worlds', which may be a reference to Fires of Pompeii when it was said the Doctor's name was sealed in the Cascade of Medusa herself or to the Doctor being the Ka Faraq Gatri.
 * The Osterhagen key would destroy the Earth. The word, Osterhagen, is an anagram of the phrase, Earth's gone.
 * This story augments the notion that Time Lords have some measure of control over the regenerative process. as seen in Last of the Time Lords.  In truth, most regenerations have added at least a little to the general mythos about the process.  From the notion that a particular physiognomy could be imposed upon the Second Doctor in The War Games, details have been added about how the process works almost every time one has been depicted.  In this case, writer Russell T Davies builds upon his earlier idea that a Time Lord can re-grow whole body parts during "the first 15 hours" following a regeneration (The Christmas Invasion). Here he suggests that a Time Lord can stop the process prior to entering the final stage, provided that he has a matching genetic receptacle into which he can store the energy.  However it is not explicitly stated if this method uses up one of the regenerations in the cycle or not due to it not being completed.
 * After the hand grows into a new doctor Donna notes that the clone doctor is naked. However careful frame by frame analysis of the scene shows that he (the actor) is actually wearing shorts.
 * When the newly created Doctor discovers he's "part Time Lord, part human" he is shocked and refuses to admit it, meaning he has never been a half-human.
 * The scene where the Daleks are speaking German is possibly a tongue-in-cheek reference to the fact that Terry Nation based the Daleks on the Nazis.
 * The word "Exterminieren", which the German Daleks use, is not in common use. In the German dubs of the episodes, the word used in "vernichten" literally, "Reduce to nothing"; colloquially, "Destroy"). The full dialogue for the German Daleks is as follows: "Exterminieren! Exterminieren! Halt! Sonst werden wir Sie exterminieren! Sie sind jetzt ein Gefangener der Daleks! Exterminieren! Exterminieren!" This translates as: "Exterminate! Exterminate! Stop! Or you will be exterminated. You are a prisoner of the Daleks. Exterminate! Exterminate!"
 * This marks the departure of Catherine Tate (Donna Noble) and Billie Piper (Rose Tyler). In an interview with Doctor Who Magazine, Piper was quoted as saying she doesn't see this as a permanent depature. Catherine Tate has no plans to return at the moment, but she has not ruled out a return in the future. Elizabeth Sladen, however, in an interview published after the episode was broadcast, said she doesn't expect to appear on Doctor Who again, although her own spinoff, The Sarah Jane Adventures would subsequently continue a few months later.
 * The story elements surrounding the destruction of the universe have some casual similarity to ideas found in Life, the Universe and Everything, a Hitch-Hiker's Guide to the Galaxy sequel penned by former Doctor Who script editor, Douglas Adams. Everything was in turn based on an abandoned Fourth Doctor television serial he had written, called Doctor Who and the Krikkitmen.
 * This is the third season finale of four to have a character in the TARDIS speaking about possible places to visit before the unexpected departure of a character. In The Parting of the Ways it's the Ninth Doctor speaking of places like the planet Barcelona before regenerating; in Last of the Time Lords, the Doctor suggests visiting Agatha Christie (among others) before Martha announces her departure; in this episode, Donna speaks of visiting Felspoon and meeting Charlie Chaplin before her mind overloads. The only episode to break this pattern so far is Doomsday.
 * Jack has flirted with or shown interest in all of the Doctor's companions appearing in this episode save Donna and Jackie. While he may currently consider Jackie off-limits because of her marriage and her connection to Rose, it is interesting to note that Jack does not pursue the two women who have exhibited the most aggressive attitudes towards the opposite sex, and who would arguably be the most likely to return his advances.
 * The actor credits for Noel Clarke, Camille Coduri, Gareth David-Lloyd and Eve Myles are timed to appear on screen as the respective actors are shown in closeup during the first two scenes.

Ratings
Journey's End was viewed by 10.57 million viewers in its first airing. This placed it as the No. 1 program of the week, beating the Wimbledon finals and episodes of Coronation Street and Eastenders. This makes Journey's End' the highest rated episode in the 45-year history of Doctor Who, surpassing Voyage of the Damned and The Stolen Earth, both of which ranked second in their respective weeks. However, the episode is not the most-watched episode of the revived series; that distinction belongs to the 13.31 million viewers obtained by Voyage of the Damned (the most-watched episode of all time remains The Ark in Space Part 2 with 13.60 million viewers in 1975, although it only ranked 5th for the week it aired). The episode also achieved an Appreciation Index rating of 91, tieing with The Stolen Earth, a number considered unprecedented for a mainstream network drama production.

Myths and rumours

 * The week between the cliffhanger ending of The Stolen Earth and the broadcast of Journey's End included some of the most intense fan speculation and media attention in franchise history. The significance of the cliffhanger, which appeared to show the Doctor regenerating, along with previously reported speculation regarding Donna and other characters led to many speculations being circulated on fan discussion boards and the media. Among some of the most notable:
 * That David Tennant was in fact leaving the series, and that leaked photos and other information regarding him being in the 2008 Christmas special (as well as media reports the preceding week that he was negotiating to return in 2010) were either a "red herring" or that the Christmas special was to include a flashback.
 * The true nature of Donna was the subject of much speculation, with some fans suggesting her to actually be The Rani or Romana living under the influence of a Chameleon Arch, or a manifestation of the Master.
 * Concerning Donna's ring, at the end of the season 4 finale, when the Doctor says good-bye to her it glimmers briefly into the camera. Some fans theorise that the ring is a possible Chamelon Arch containing Donna's memories of her time with the Doctor. It has also been suggested that the ring resembles a ring worn by The Master in a previous episode. Others theorise that the ring is just large, black, and very shiny. But this cannot be so as Donna was not wearing it towards the end of Journey's End before her mind was wiped and why would the Doctor put a ring on Donna anyway?
 * The prediction that a companion would die led some to believe Donna, Martha or Rose would be the ones destined to die (since it had already been reported that John Barrowman would be returning to Torchwood and Elisabeth Sladen to The Sarah Jane Adventures, ruling out their characters' demise.) Ultimately, this was a partial red herring, as it was an aspect of Donna that died, but not the character herself.


 * A number of fans have begun to speculate as to whether or not the Meta-Crisis Tenth Doctor will eventually become to be known as the enigmatic, malevolent Valeyard.
 * The appearance of K-9 was a surprise to many as it had been previously reported that the character would not be appearing in the episode, given the fact the rights to the character are currently held by another party for the planned K-9 television series.
 * It was strongly believed that Harriet Jones was wanting revenge upon the Doctor for bringing down her reign as Prime Minister, so she decided to help bring the Daleks back, and she was in fact the Supreme Dalek. A supposed "leaked script" showed that Harriet Jones was in fact helping the Daleks. This was proved false.
 * The fact that Jack, Martha and Mickey depart together has sparked speculation that Martha and Mickey may appear in Torchwood, possibly replacing Tosh and Owen. The subsequent announcement that Freema Agyeman had been signed by ITV, a rival network to the BBC, to take a lead role in the series Law & Order: London, has reduced the chances of her appearing in Torchwood. She did subsequently take part in the BBC Radio adventure Lost Souls, but that story takes place prior to the events of The Stolen Earth.
 * The survival of Davros, supposedly killed in the first year of the Time WAr, raises the possibility of other Time Lords surviving.

Discontinuity, Plot Holes, Errors

 * Why does Rose say "What is that thing" even though she has seen it before - a Dalek out of the shell. It was acting oddly - so Rose wondered why.
 * Wouldn't the nuclear warheads placed under the crust have melted? Not if they were protected in some way. If it's possible to build a doomsday device it's possible to build a shield agsinst such heat.
 * If any mention of the Doctor or the TARDIS would cause the Time Lord consciousness within Donna to reawaken and burn up her mind, isn't the Doctor taking a tremendous risk by letting Donna see him in the Nobles' house? Maybe The Doctor wishes to test the effectiveness of the memory wipe and also determine whether there are any negative effects on her. If the erasure didn't take, he could rectify the situation immediately.
 * With all of her memories since The Runaway Bride erased, wouldn't Donna realise that she has lost about a year and a half of of her life, and shouldn't she think it's her wedding day? The Doctor states that he erased memories of him and the TARDIS, meaning that he never erased 2 full years of her life. She presumably remembers a mundane version of that time, and will naturally dismiss any gaps. We don't know if the Doctor didn't implant false memories.
 * Also at the end of the episode Donna talks to her friends on her mobile, but wouldn't they wounder where she ahs been for the last six months or so, while she was travelling with the Doctor? There is no indication of how long Donna actually travelled with the Doctor, let alone how long she was away from Earth in Earth time. Martha, for example, was established to have only been away from Earth for a period of a few weeks, subjective Earth time, although much longer passed for her in TARDIS time.
 * If the Earth was one of 27 planets stolen, why in Turn Left the Earth has not been stolen but the effects of the Reality Bomb are still seen anyway? Davros stole the Earth in the Doctor's universe, not the universe that was created around Donna as a result of the Time Beetle in Turn Left. The reality bomb affects all universes.
 * How could Sarah Jane and Mickey possibly run across the hall, up stairs, open a door, and close it without the Dalek looking at the terrified woman, the dozen or so Daleks in the background, the sec. cams and the Dalek that goes past the door noticing? Dalek Caan possibly hacked into the system and made sure that Mickey and Sarah Jane were not seen at all costs, Dalek Caan forsaw them and knew what to do.
 * Considering Rose was about to start working for the parallel Earth's Torchwood when she last saw the Doctor, it's odd that she wouldn't mention this to Jack. It is not confirmed on screen that Rose ever did join Torchwood; also not all interactions between the companions were shown on screen (such as the period between the restoration of Earth and the departure of the companions).
 * Why didn't Davros activate a holding cell on Donna when he did with everyone else? He thinks there is no way that anyone can stop the plan now that the gun is destroyed. He may have also assumed Donna to be unconscious or dead after having blasted her, and therefore no longer a threat.
 * The Doctor states that Donna was the most important woman in the whole universe. This is incorrect because she was the most important woman of all the universes. One wouldn't expect Donna's mum and her grandfather to understand the concept, so the Doctor simplified it.
 * Dalek Caan predicts the death of Donna but if the reality bomb went off, all the Doctors companions would have been killed. It's strongly suggested in dialogue that Caan knew all along that Davros' plan would fail.
 * One of the memory flashes as Donna's mind is erased is of her about to be transported through time in Turn Left; yet she didn't remember these events once the timeline was restored. But she remembered some of them otherwise she would never have been able to deliver Rose's message to the Doctor. In The Stolen Earth she recalls more details about the alternate timeline, too.
 * If the Ostahagen Key destroys the entire plane to put it out if it's misery, why wouldn't they have used it in the events of The Dalek Invasion of Earth? The Doctor does tell Martha to get rid of it - presumably she managed to.
 * The DoctorDonna imobilises all the Daleks but yet the Supreme Dalek descends to the vault and destroys the Magnetron Perhaps the Supreme Daleks has a different kind of Dalek base than other, it could be said why isnt Cann and Davros affected. It would make sense for the commander to be independent of any system.
 * DoctorDonna incapacitates the daleks by manipulating keys. Why are there keys that could only be manipulated by hands on a Dalek vessel? Davros has humanoid hands.
 * When the Earth was returned to its rightful position, the moon is seen to be still in its place (did not travel with the earth as we must assume the satellites and the rift did) and presumably resumed orbit. Wouldn't it have floated off toward the sun or another planet without the Earth's gravity to keep it in place? Earth perhaps wasn't gone long enough for this to become an issue. The Doctor acknowledges that the Earth is in for a period of unusual weather patterns, likely caused by the Moon reinstating itself. It's also possible that, off screen, the Doctor used the TARDIS to put the Moon back in its proper location.
 * How could Mickey stay on the Doctors earth and Rose not what makes Rose and Mickey different?  The Doctor told her she was needed by the Metacrisis Doctor in Pete's World.
 * How does the Doctor know the new Dalek empire is 'at the height of its power?' When did this new Empire begin? In other words, at what time relative to earth time did Caan rescue Davros from the Time War? If the Time War occured between the Eighth and Tenth regenerations, as is generally supposed (that is, between the last decade of the 20th century and the first of the 21st), there would be little time to restablish the Dalek Empire.
 * If there is a new Dalek Empire, other worlds besides those transportedc are presumably subject to the Daleks. It is not confirmed whether these Daleks have been destroyed.
 * The Supreme Dalek orders the Daleks to return to the Crucible to shield themsel;ves from the Reality Bomb. But why wouldn't the Reaity Bomb dissolve the Crucible if it destroys all matter.
 * To be scientifically, and boringly correct, the Daleks could not have existed in a universe where they are the only forms of matter anyway. Every source of energy, and even light itself, would cease to exist.The air through which sound ways travel would cease to be. There would be no space or time. They would simply have no space to exist, as even space itself would cease to be. There would not be an empty blackness, for even blackness is something. There would be nothing at all.

Continuity

 * When the Doctor sees Gwen Cooper for the first time, he asks if she comes from a long line of family from Cardiff. This is because of the similarity between Gwen and Gwyneth (DW: The Unquiet Dead), both of whom are played by Eve Myles. Which is explained by Russell T Davies as:"It's not familial as we understand it. There's no blood tie. Spatial genetic multiplicity means an echo and repetition of physical traits across a Time Rift."
 * This is the first occurrence of the Doctor's TARDIS being piloted by six people, that number first being specified in NA: Cat's Cradle: Time's Crucible. This is the first on-screen confirmation that TARDISes are designed for six pilots; this retroactively serves to explain the Doctor's difficulty in correctly piloting the craft dating back to the very first season in 1963.
 * This episode marks the last appearance of the Tenth Doctor's severed hand which first appeared in DW: The Christmas Invasion and throughout the first season of Torchwood.
 * Davros mentions meeting Sarah Jane at the birth of his creations; this happened in DW: Genesis of the Daleks.
 * Mickey Smith and Jackie Tyler last appeared in DW: Doomsday.
 * Donna tells the Doctor how to fix the Chameleon Circuit which has been broken since DW: An Unearthly Child. The Sixth Doctor had previously attempted this in DW: Attack of the Cybermen, as had the Fourth Doctor in DW: Logopolis. Dialogue in Rose and Boom Town implied he was no longer interested in changing its external appearance and rather liked the police box form, plus in the QuickReads book, ''Made of Steel, The Doctor talks about fixing the Chameleon circuit, but says he would be worried about forgetting what it looked like.
 * The fact a single TARDIS has enough power to relocate Earth harks back to DW: The Mysterious Planet which established that approximate 2 million years into the future the Time Lords will once again move Earth to another part of the universe, where it will come to be known as Ravolox.
 * This is the fourth time a Doctor has been depicted in a way to suggest he was unclothed. The first time was in Spearhead from Space in which a newly regenerated Third Doctor took a shower. The second was during the regeneration from the Seventh to the Eighth Doctor, where he was merely covered by a sheet. The Ninth Doctor appeared shirtless during the torture scene in Dalek.
 * Gallifrey is mentioned again.
 * The Doctor tells Wilf that he's "fine" after he drops off Donna. This echoes a similar statement in Forest of the Dead which Donna interprets as meaning the complete opposite.
 * The Verron Soothsayer, who gave Sarah Jane Smith the Warp star, was mentioned previously in SJA: Whatever Happened to Sarah Jane?
 * The device created by the Meta-Crisis Doctor looks similar to the device used against the Daleks in (DW: Remembrance of the Daleks) and that device was similar to one the Third Doctor built on Spiridon in (DW: Planet of the Daleks)
 * Jack introduces Gwen as Gwen Cooper. This is the first on-screen confirmation that Gwen has not changed her last name to Williams, per the events of TW: Something Borrowed.
 * The Dream of a Normal Death is heard again as the Doctor pilots the TARDIS at the end of the episode. This was first heard at the end of The Family of Blood when John Smith and Joan are holding the watch and seeing the future.
 * An interesting and speculative tie-in might be made with Genesis of the Daleks. In Genesis the Fourth Doctor is told by the Time Lord that they, the Time Lords, foresee a time when the Daleks will have destroyed all other life and become the dominant life forms in the universe. Are the Time Lords here foreseeing the success of the Reality Bomb? If so, do the Fourth Doctor's actions to retard Dalek evolutiondisplace that timeline with a timeline in which the Bomb does not succeed?

For Doctor Who

 * Journey's End occurs after: DW: The Stolen Earth
 * Journey's End occurs before: DW: Music of the Spheres (although it can be argued that Music of the Spheres could take place anytime during the Tenth Doctor's life) and DW: The Next Doctor

For Torchwood

 * Journey's End occurs after: TW: Exit Wounds and the radio play Lost Souls
 * Journey's End occurs before: TW: Children of Earth

For The Sarah Jane Adventures

 * Journey's End occurs after: SJA: The Lost Boy (conjectural)
 * Journey's End occurs before: SJA: The Last Sontaran (conjectural)
 * See The Last Sontaran for discussion as to whether this story takes place before or after these events.

DVD and Other releases

 * Released in the Series 4 boxed set in November 2008 along with the rest of the Series.
 * Released as Series 4 Volume 4 in a vanilla edition alongside Turn Left and The Stolen Earth on 1st September 2008.