I’ve never thought Fred MacMurray was a particularly strong performer; he doesn't seem especially adaptable or engaging on screen. However, in this film, he does a commendable job as the undercover officer "Sheridan." The story becomes more intense when his character meets the mysterious "Lona" (Kim Novak), and they quickly become involved in a romantic relationship. It’s revealed that she is connected to a thief who masterminded a $200k robbery, and he's meant to use her to locate him. After learning of his true identity, she attempts to ensure his loyalty remains with her. Meanwhile, he faces a conflict between his duty and something else entirely. The film manages to fit a great deal into ninety minutes, featuring considerable suspense and a palpable sense of avarice as you're left wondering who will double-cross whom. Novak delivers a solid performance, as does Dorothy Malone in her limited role, and E.G. Marshall is good as his knowledgeable lieutenant "Eckstrom." Richard Quine maintains the tension effectively until the very end of this excellent crime noir, which has a plot and script that are above average and deserves to be seen.

Source on TMDB