Series 1

DCI Sam Tyler's (John Simm) world is about to be turned upside down. Moments after his girlfriend and colleague, Maya (Archie Panjabi), is kidnapped by a serial killer, Sam is knocked unconscious by a car.

He wakes up - in 1973.

Sam discovers a strange new world full of cigarette smoking, gum chewing, and unreconstructed men. He's a DI starting his first day in a new precinct and he's got to prove himself to his new DCI, Gene Hunt (Philip Glenister). Gene likes to throw his weight around. He acts first and thinks later. The only person in this alien world who reaches out to Sam is a young WPC, Annie Cartwright (Liz White).

Dazed and confused, Sam finds it difficult to focus on the murder his new colleagues are investigating. Then he discovers a connection between this crime and the serial killer who kidnapped his girlfriend back in 2006. Could solving this case be the key to getting home? Could it be a way to save Maya?

It seems that the biggest obstacle standing between Sam and success is his new DCI's very different attitude to policing. To Sam, a 21st Century liberal, Gene represents everything that is bad about the police force, everything that the force has tried to stamp out over the last 30 years.

Sam's faced with a huge moral dilemma when he realises that destroying evidence in 1973 could save Maya's life in 2006. At the same time, he becomes ever more doubtful about the reality of his situation. Do distant doctor's voices from 2006 bleeding through into 1973 mean that he's in a coma and none of this is real?

As the ultimate test, he stands on the roof of the police station poised to jump off. Annie talks him down, and, at least for the moment, he remains stuck in a time that's completely alien to him.