Long before there was "Throw Momma from the Train," there was this Hitchcock super-thriller about two passengers who accidentally meet and plan to "trade" murders. Amoral Walker wants the exchange and the money he'll inherit by his father's death; Granger would love to end his stifling marriage and wed Roman, a senator's daughter, but finds the idea ultimately sickening. What happens is pure Hitchcock. Screenplay co-written by murder-mystery great Chandler. Patricia Hitchcock, the director's only child, plays Roman's sister. The concluding "carousel" scene is a masterpiece. From the novel by Patricia Highsmith.