Doctor: Christopher Eccleston (Ninth Doctor)
Companions: Billie Piper (Rose Tyler)
Bruno Langley (Adam Mitchell)
Corey Johnson – Henry van Statten
Anna-Louise Plowman – Diana Goddard
Steven Beckingham – Polkowski
Nigel Whitmey – Simmons
John Schwab – Bywater
Jana Carpenter – De Maggio
Joe Montana – Commander
Nicholas Briggs – Dalek voice
Directed by Joe Ahearne
Written by Robert Shearman
Script editor Helen Raynor
Produced by Phil Collinson
Executive producer(s) Russell T Davies
Incidental music composer Murray Gold
Production code 1.6
Series Series 1
Length 45 minutes
Originally broadcast 30 April 2005
The Doctor and Rose land the TARDIS in a massive underground bunker near Salt Lake City, Utah in the year 2012. They were drawn there by a distress signal being transmitted from the bunker. They look around at various alien artifacts that have been set up on display in glass cases. After touching one case, they are surrounded by soldiers who take them to see Henry van Statten, the owner of the collection. The Doctor talks to van Statten, while Rose tours the facility with a technician named Adam Mitchell. Van Statten wants the Doctor's opinion on the pride of his collection, which he calls the "Metaltron" and orders him locked into the vault with the specimen. The Doctor is horrified to find that the Metaltron is actually a Dalek, as he thought the species had been wiped out in the Great Time War. The Doctor finds out that the Dalek is weakened and chained down, unable to fight back. The Doctor attempts to destroy it, but is stopped by van Statten's guards and escorted back to his offices.
Meanwhile, Adam takes Rose to the vault to see the Dalek. She takes pity on the Dalek, touching its casing. The Dalek absorbs her DNA and the time energy she has been exposed to from travelling in the TARDIS. The Dalek becomes re-energised, and is able to break the chains holding it captive. It kills its torturer, Simmons, by crushing his skull using its plunger. In another part of the complex, van Statten reveals to the Doctor that not only does he collect aliens, but he also tortures them; he proceeds to invasively and violently scrutinize the Doctor's body so that he can learn more about his physiology. Upon hearing the alarms sound, van Statten releases the Doctor who tries to stop the Dalek. The Dalek breaks out of the cage it was sealed in and plugs itself into the Internet, learning that it is (apparently) the last Dalek. Without other Daleks coming, it reverts to its original mission - the destruction of all non-Dalek life. The Dalek chases Adam and Rose, killing the guards in the way. It ruthlessly kills a large group of soldiers in a warehouse before declaring it will speak only to the Doctor. The Doctor then suggests the Dalek kill itself to remove the presence of its race from the universe, but the Dalek decides to proceed with exterminating everyone.
Adam tries to help Rose escape, but she is trapped inside the vault when it is sealed by the Doctor. The video feeds are disrupted moments before the Dalek encounters Rose. The Dalek finds that it cannot exterminate Rose, and is conflicted by the human DNA it absorbed from her. The Dalek forces the Doctor to let it out of the vault in exchange for Rose's life, and it makes its way to van Statten's office to kill him. Rose convinces the Dalek to spare van Statten and accompanies it to the highest part of the vault, where it blasts a hole in the ceiling. The Dalek opens its casing and basks in the sunlight as the Doctor arrives with an alien weapon. Rose pleads for the Dalek's life, arguing that it has changed because it couldn't kill her or van Statten. The Dalek is disturbed by the new emotions and ideas that it has developed from absorbing Rose's DNA and is now repulsed by its own existence. It asks Rose to order it to self-destruct. She reluctantly agrees, and the Dalek engages its self-destruct mechanism and implodes.
Van Statten's assistant takes over, ordering van Statten's mind wiped and having him dropped off on the side of the road somewhere beginning with S. The Doctor and Rose head back to the TARDIS with Adam following them. He tries to convince them to leave immediately because the vault is about to be filled with cement, but instead Rose invites him to travel with them.