Two Americans (Fred MacMurray, Claire Trevor) are caught in the middle of a dope-smuggling ring in a Mexican border town. Each suspects the other is involved with the drug cartel, not realizing that they are both, in fact, undercover agents. They both find evidence that will send drug czar Pete Richie (Raymond Burr) to prison for life. The couple falls in love and are tortured by the prospect of turning each other in to the authorities at the border crossing. MacMurray's icy cool performance and Trevor's jittery energy create a chemistry that ignites this classic film noir.

A pair of undercover agents team up to bust dope smugglers along the U.S./Mexico border -- all the while suspecting each other of being crooks. Good interplay between Fred MacMurray and Claire Trevor highlight this film noir.