Hit BBC One time warp drama Life on Mars is to end after the next series.
The second series promises "shocking revelations"
The producers said two endings to the second series had been filmed "to keep everyone guessing until the very end".
Life on Mars, starring John Simm as a modern police officer who has woken in 1973 after an accident, was a critical hit and had audiences of seven million.
Executive producer Claire Parker said the story would reach a "natural and explosive climax". Series two is due to be broadcast early in 2007.
Viewers will learn how Simm's character, Detective Inspector Sam Tyler, became stuck in the '70s.
Writer and co-creator Matthew Graham said: "We decided that Sam's journey should have a finite life span and a clear-cut ending and we feel that we have now reached that point after two series.
"Although it is sad that we have just finished filming Sam's final scenes, it's also been an incredibly exciting few days."
It is reported that Ally McBeal creator David E Kelley is making a pilot based on the show for US audiences.