Doctor: Christopher Eccleston (Ninth Doctor)
Companion: Billie Piper (Rose Tyler)
Camille Coduri – Jackie Tyler
Shaun Dingwall – Pete Tyler
Robert Barton – Registrar
Julia Joyce – Young Rose
Christopher Llewellyn – Stuart
Frank Rozelaar-Green – Sonny
Natalie Jones – Sarah
Eirlys Bellin – Bev
Rhian James – Suzie
Casey Dyer – Young Mickey
Directed by Joe Ahearne
Written by Paul Cornell
Script editor Helen Raynor
Produced by Phil Collinson
Executive producer(s) Russell T Davies
Incidental music composer Murray Gold
Production code 1.8
Series Series 1
Length 45 minutes
Originally broadcast 14 May 2005
The episode opens with a flashback of Jackie Tyler telling a younger Rose about her father Pete, who died in a hit-and-run accident on the way to a friend's wedding.
In the TARDIS, the Doctor agrees to take Rose to the day her father died so that she can be there when it happens. Upon their arrival in London on Saturday 7 November 1987, they witness the accident, but Rose is unable to move when the Doctor tells her to go comfort her dying father. Rose asks the Doctor if she can try again, and the Doctor allows it but warns Rose to not run until their former selves have left to prevent a paradox. As the accident is about to happen, Rose suddenly runs out and pushes Pete aside, saving his life. The younger versions of the Doctor and Rose vanish. Rose and the Doctor fight about her actions, with the Doctor rebuking her for potentially damaging the timeline. The Doctor takes Rose's TARDIS key back and storms off without her. Rose decides to go with Pete to the wedding, while the Doctor walks back to the TARDIS only to find that it is now an empty shell. Strange flying beasts called Reapers appear and begin consuming people.
Rose and Pete drive to the wedding together, and the car that had been meant to kill Pete nearly collides with their car. They join the other guests, including Jackie who has brought the infant Rose with her. Rose is surprised to find that Jackie and Pete argue frequently. A young Mickey runs in to warn the guests about the Reapers, who think it is a joke until a Reaper appears above and attacks them. The Doctor runs to the church and directs everyone inside, noting that the age of the church will protect them against the Reapers. The Doctor explains to Rose that her actions have caused a paradox that normally the Time Lords would have prevented. Without them, the Reapers are sterilising the wound in time by consuming everyone within it. The Doctor further warns Rose not to touch her infant self, as it could cause further damage to time and allow the Reapers into the church. Feeling that his TARDIS key is still warm, the Doctor sets it up in the middle of the church and the TARDIS slowly begins materialising around it.
While waiting in the church, Jackie sees Pete talking to Rose and thinks he is having an affair. Pete and Rose talk alone, and he comes to realise that she is his daughter. When Rose is unable to answer questions about how good of a father he was, Pete realises he was meant to die in the accident. Jackie thinks Rose is Pete's daughter with another woman, and in a fit of frustration Pete hands the baby Rose to adult Rose. The paradox worsens, and a Reaper is able to enter the church. The Doctor declares himself the oldest thing in the church and offers himself to the Reaper, who consumes him and disappears. The TARDIS key goes cold and drops to the ground. Pete realises that they now have no other choice and that he must die in order to restore the timeline. He bids Rose and Jackie an emotional farewell, races out of the church and throws himself under the car that was originally meant to kill him (which had been constantly appearing and disappearing in front of the church). The timeline is repaired, and those previously consumed by the beasts reappear. The Doctor sends Rose off to be with her dad as he dies, and she holds his hand until he is gone. Rose and the Doctor walk hand-in-hand back to the restored TARDIS.
The episode ends with a flashback similar to the opening, as Jackie explains to a young Rose that Pete did not die alone. She tells Rose about a young woman who stayed with him until he died. In a voice-over, the adult Rose eulogises her father.