Deathtrap is not a whodunit. It's a who gonna do it to who first. It's so hard to describe this movie without giving anything away so I won't mention anything more about the plot. As far as acting goes it is Cris Reeves greatest role as Clifford, a young playwrite. You really see the range in his acting abilities in this movie from "exhaling cheeseburgers" to downright frightening. Clifford is such a hard role to play and in the stage production of this I have never seen Clifford played well on both ends of the spectrum. The actor plays him as a little puppy or a homicidal maniac. Reeves is the only person I have seen who has the character right all the way through. As for Michael Caine he's.....well he's Michael Caine. One of the best actors of the last 50 years and in this film as good as he has ever been.