DI Alex Drake is driving her car, while her daughter Molly is reading Sam Tyler's experiences in 1973 in a Police document.
He rings up an unknown person and tells them that he has Tim and Caroline Price's daughter; Drake asks Layton, "How do you know my parent's names?"
She is taken hostage by Edward Markham, when she is surprised that DCI Gene Hunt, DS Ray Carling, and DC Chris Skelton appear, looking exactly like Sam described except for the updated clothes (1980s).
She convinces Markham to surrender and is taken to the Metropolitan police station, where she discovers that she has a life set up just like Sam Tyler did.
In the final episode of Life on Mars, Sam Tyler is shown recording his thoughts and experiences in 2006 for an unnamed colleague in psychological services.
During the opening scenes of the first episode, it is revealed that Alex Drake is a police psychologist who has been studying Sam Tyler's suicide and the records of his life in his 1973 world.
Upon Drake being shot during a hostage situation in 2008, she awakens in 1981, where she is amazed to meet Gene Hunt, who was mentioned in Sam Tyler's case notes.
As Drake has read the report of Sam Tyler's reality, she knows that telephones and radios carry messages from the present day to her and how she can see hallucinations of those that she loves.
Tyler spent a further seven years in this alternate timeline, before crashing his car while pursuing robbery suspects, with his body never being recovered.
The 2nd-through-final episodes' opening credits begin with an explanatory monologue by Alex, closely following that of Sam on Life on Mars.
Sam's memories, from 1973, are shown as grainy film; Alex's, from 1981, are depicted as home video complete with whirling sound of a VCR fast-forwarding and reversing the tape.
Chris Skelton (Marshall Lancaster) and others sing "Shaddap You Face" by Joe Dolce, a 1981 novelty hit which parodies Italian English.