I always felt that Fred MacMurray was a bit of a lurch as an actor. Never particularly versatile nor charismatic to watch. Here, though, he is pretty effective as the undercover cop "Sheridan". Things hot up for his character when he encounters the enigmatic "Lona" (Kim Novak) and soon they are having a passionate affair. What we soon find out is that she is the gal of a thief behind a $200k robbery and he is supposed to be using her to get to her beau. When she discovers he is a policeman she tries to make sure that he is, and stays, in her corner. He, on the other hand, has a job to do - or ...