We've come so far and now the end is near. The journey that began with "Life on Mars" concludes as Alex Drake embarks on her final mission: to uncover the truth about Gene Hunt and unlock the dark secrets of this world. Alex is back, only this time it's 1983 and something feels different. The arrival of DCI Jim Keats, sent by Scotland Yard to monitor the station's performance, throws some unexpected light on past events. Haunted by the ghost of a policeman, Alex decides that her only hope in getting home lies in finding out what really happened to Sam Tyler. As the final series reaches its climax, will Alex finally manage to unlock the mysteries of this world and find her way home, or will everything she's held to be true come crashing down around her feet?