Lamont Cranston (Rod LaRocque) is an amateur criminologist and the host of a daily radio program sponsored by a local newspaper. What the public doesn't know is that Cranston is also The Shadow, crime fighter with extraordinary abilities and a bane to every criminal. Cranston becomes involved, through his radio program, with the death of a prominent businessman that at first appeared to be a simple safe robbery. Uncovering more details about the case, Cranston discovers a connection to this death with a group of foreign spies and saboteurs. Cranston must assume the guise of his alter-ego in order to bring the enemy agents to justice.