Strangers on a Train

Have you ever said that you wished someone was dead?   Of course you would never do it.   But, suppose you met someone on a train who offered to do the killing for you?   This is what happens to Guy Haines, a tennis star who hates his estranged wife and wants to be free so he can marry another woman.   On the train, he meets Bruno Anthony, who happens to hate his father.   Bruno has a simple plan: each could kill the other's victim.   No motive, no clues, nothing to link Guy and Bruno but .  .  .   a chance meeting on a train.   Guy laughs it off.   But, shortly after, Guy's wife is found murdered.   And Bruno shows up demanding Guy keep his end of the plan.