Straight cop Paul Sheridan (Fred MacMurray) is on the trail of the loot stolen in a bank robbery where a guard was shot and killed. He is tasked with getting to know Lona McLane (Kim Novak), the girlfriend of the chief suspect in the robbery. But once contact is made, and surveillance is arranged on her apartment, things hot up for his character when he encounters the enigmatic "Lona" and soon they are having a passionate affair.