After a narcotics agent and his informer are murdered in Los Angeles, the Federal Bureau of Narcotics assigns Special Agent Phil Sherrin (William Henry) to help West Coast Bureau Chief Charles Stuart (Robert Shayne) investigate. A photo of a dancer's dead informer takes Phil to Tijuana, Mexico, where he gets information that leads him to a mysterious box sent to California. Tipped off to the identity of the head of a drug-smuggling ring, Phil is nevertheless powerless to stop the next murder.