Series 3 was the third and final series of Ashes to Ashes that began on 2nd April and ended on 21st May 2010. It was also the overall conclusion of the programme that began with Life on Mars four years earlier.
At the beginning of the new series, we see Detective Inspector Alex Drake trying to adjust to life back in the 21st Century, but she is still having visions of Gene Hunt and company, who visit her in hospital following the shooting of her by Hunt back in the finale of Series 2. Gene Hunt then slaps her out of her coma, revealing that Alex is still stuck in the 1980s. The year is now 1983 and it is revealed that Gene has been on the run following the events of Operation Rose and was accused of trying to murder Alex. When they go back to Fenchurch East CID, they find that a lot of things have changed. Ray Carling has now been promoted to DI and is in charge, occupying the office that Gene used to have. Chris Skelton and Sharon Granger are no longer together and have broken off their engagement and a new character is also introduced, Jim Keats from the Discipline and Complaints Department. He has apparently been sent to investigate CID and the shooting of Alex Drake, but it soon becomes clear that he is there for more than just that. Along the way, the team investigate the kidnapping of a young girl, a series of arson attacks against the backdrop of the 1983 General Election and as well as try to stop a vicious prison riot that ultimately results in the death of Viv James, the desk sergeant. Also strange things start to happen such as stars appearing and Shaz, Chris and Ray each hearing music as they find redemption at the end of an episode that focuses on them. Meanwhile Alex Drake does her private investigation into the 'death' of Sam Tyler. She believes that by doing this she can get back to 2008 and her daughter Molly, which is what she has been doing since the start of Series One. In episode seven, Gene and Alex go on a date, where Alex finally asks him if he murdered Sam, in which Gene reveals that he was asked to help Tyler fake his own death. The pair also get intimate and nearly share a kiss, had it not been for the arrival of Keats knocking on the door of Alex's flat. Keats is determined to bring down Gene Hunt and his world. In the last ever episode it is revealed that Gene and his colleagues are all dead, and so is Alex Drake who died in episode one of the third series. It would assume that Gene is some kind of guardian angel, guiding the lost souls to Heaven while Keats is the Devil, who had come to try and lure Alex and her colleagues to Hell. CID is merely a limbo for dead police officers who had suffered trauma and that Chris, Ray and Shaz were also from different times. Gene and the team do one last job which involves foiling a diamond heist and he takes them to the pub, The Railway Arms, where the they are greeted by Nelson. It is also revealed that Gene has been doing this for many other dead officers before, including Sam and Annie Cartwright. It is assumed that Viv James is in Hell, after Keats comforted him in the concluding moments of episode six. After seeing Chris, Ray and Shaz on their way, Alex believes she can still go home, but eventually realises that she too is dead and will never see Molly again. Once resigned to this fact, she and Gene finally share a kiss and she enters the pub. Gene is left on his own again and returns to his office, where it seems he is apparently stuck in eternity and to continue guiding dead police officers to Heaven. A new police officer arrives from the 21st Century in the same fashion that Sam Tyler did, demanding to know where his office is and wanting his iPod back. Gene uses the phrase "a word in your shellike, pal," the very first words he spoke in the first ever episode of Life on Mars.