DI Alex Drake is taken hostage and shot, and wakes up in a brothel... in 1981. Rescued in a police raid, she quickly recognises DCI Gene Hunt and his team from detailed reports made by DCI Sam Tyler about his own trip to 1973.

Gene is determined to address London's growing drugs problem, and has targeted city playboy Edward Markham as the brains behind the operation. Alex suspects Arthur Layton, the man who kidnapped her in 2008. Could Layton be the key to her return to her own time?

The team investigates the armed robbery of a fundraiser who has been travelling across the country in a bathtub full of baked beans to raise money for Children in Need. Alex thinks that a crime reconstruction on Police Five will do the trick, but Gene prefers some old-fashioned police work.

The team is on the hunt for major vehicle thief Jed Wicklow, but when a car chase leads to his death, Gene stands accused of causing it through reckless driving.

Alex is adamant that there was something wrong with Jed at the wheel and wants to prove that the crash wasn't Gene's fault. The deceased Jed was a Romany gypsy, and hostilities run high on the camp as CID heavy-handedly try to uncover the circumstances of his death. But in an investigation that's already met with resistance, someone in the police force also appears to be standing in their way.

After Alex catches an infection back in 2008, she knows the doctors think she wont pull through. Distance grows between Alex and Gene and their relationship is put under the greatest strain yet.

Alex soon realises she has not returned home after all, and wakes up in 1983. Gene is on the run, and DCI Jim Keats has arrived from Complaints to investigate CID following the shooting. Newly-promoted DI Ray Carling leads an investigation into the kidnapping of a young girl, and sets up a sting operation. Alex decides that she will have to discover the truth about Gene if she is ever to get back to her own time.

DCI Gene Hunt and his team are investigating a diamond heist following the murder of three London gang members. But DI Alex Drake is distracted and, with encouragement from DCI Jim Keats, she decides to pursue her own investigation to the bitter end - did Gene Hunt murder Sam Tyler?

When Gene discovers that Alex has gone, he races after her leaving Ray Carling, Chris Skelton and Shaz Granger to plan an ambitious sting operation.

As Gene desperately tries to reach Alex before she discovers the truth, Chris, Shaz and Ray's world completely falls apart. It's time for Alex and the rest of the team to find out the truth about Gene Hunt...