Life on Mars meets Camberwick Green

Spoiler alert: do not read this if you don’t want to know how it ends or what happens in the first eight episodes of Ashes to Ashes.
In the eighth episode of the second series of Life on Mars, Sam wakes up after Dr Frank Morgan tries a procedure. He’s in Hyde Ward 2612. However, he realizes he doesn’t feel alive in 2007 and decides to commit suicide, waking back up in 1973 to be with Annie.
However, in the sequel series Ashes to Ashes, DI Alex Drake, who is reviewing Sam’s case file, is shot and wakes up in 1981, meeting DCI Gene Hunt, Ray and Chris. Sam has died (in 1980, but his body was not found) and Annie is not present. Through the series it is hinted that Alex’s predicament is different from Sam’s because there are scenes that occur that are not through Alex’s eyes. (In Life on Mars, no scene was without Sam.) By the last episode of the first series, it emerges that she might actually have met Gene Hunt while she was a child, and he in fact held her hand after her parents were killed.
So while Life on Mars ends with us thinking that it was all in Sam’s head and that 1973 is his idea of Heaven, Ashes to Ashes casts some doubt as it is now possible that Gene exists in some universe.