Anxious to see some naval action in the Pacific during WWII, Lt. Bill Gordon makes the mistake of telling his new girlfriend, ditzy Elaine Carter, that he was an expert in deciphering codes. Trying to keep him in the states for herself, she convinces her uncle to add him to a unit charged with deciphering the enemy's coded messages. With the murder of his superior, Gibson attempts, with the "help" of Elaine, to root out the spy ring that's been intercepting valuable troop movement information.