In a flashback, Rose Tyler’s (Billie Piper) mother Jackie (Camile Coduri) tells young Rose (Julia Joyce) about her father Pete (Shaun Dingwell), who was killed in a hit-and-run accident on the way to a friend’s wedding in 1987 and died alone on the street. At her request, the Doctor takes Rose to the day Pete died. Rose rushes out and pushes Pete aside, saving his life. The Doctor rebukes rose for possibly damaging the timeline. Rose decides to go with Pete to the wedding, while the Doctor walks back to the TARDIS, pretending he will leave her behind. When he opens the door, he finds it just a police call-box inside. He runs back to Rose and the sky is filled with reapers who begin consuming people.

Rose and Pete drive to the wedding together, and the car that was supposed to kill Pete nearly collides with them. A reapers attack the wedding guests, including Jackie and the infant Rose. The Doctor runs to the church and ushers everyone inside because the age of the church will protect them from the reapers. Rose’s actions have caused a paradox, which the reapers are repairing by consuming everyone within it. The Doctor finds that the TARDIS key is still warm, so he sets it up in the middle of the church and the TARDIS begins to materialize around it. Who knew?

Pete realizes that Rose is his and Jackie’s daughter, but when she talks of what a great father he was, he realizes that she is lying and that he was supposed to die. At first, Jackie thinks Rose is Pete’s daughter with another woman, but Pete convinces her otherwise. She hands Baby Rose to Rose, who takes her without thinking, coming into contact with her own self. This makes the paradox even worse and the reapers enter the church. The Doctor, as the oldest thing in the church, offers himself to the reapers and is consumed. The TARDIS vanishes and the key falls to the floor.

Outside, the car that was supposed to kill Pete keeps appearing and re-appearing. Realizing that he was not there for Rose, he does what he can for her now, runs out and throws himself in front of the car. He is fatally injured, and the timeline is repaired, the reapers’ victims restored, including the Doctor and the TARDIS. Rose holds her father’s hand until he dies.

The character of Pete Tyler was based on the writer Paul Cornell’s real father. The church was Saint Paul’s Church in Grangetown, Wales. Members of the cast and crew brought in pictures of themselves from the Eighties for the costume designers. Originally, the reapers were supposed to be the Grim Reaper, with a scythe. The final design was based on a shark, a bat, and a praying mantis, with a voice like a vulture. When the timeline is damaged, all phones begin to repeat, “Watson, come here. I want you.” A concert poster mentions Bad Wolf. The child who played young Rose also played the young version of Billie Piper in Mansfield Park.

In Doctor Who canon, fixed points in Time, which you dare not change, include people’s death, though in a natural disaster one might save a few of a multitude of people without creating a paradox. One’s actions, however, may be fixed points, which shows why the Doctor cannot go back to the same point and correct his mistakes. Interestingly, because Pete ran out in front of the car, the driver was not arrested as a hit-and-run perpetrator and it probably changed his life for the better. This was a monumental tear-jerker and was well received by the public and reviewers. Piper said it was her favourite episode, though it was exhausting. Shaun Dingwell’s performance was riveting. The story was nominated for the 2006 Hugo, but it came in third after the later Doctor Who episodes The Empty Child/The Doctor Dances.