Among the troupe of entertainers arriving at a naval base are the Great Rajah, a knife thrower, his wife Lana and stowaway Gloria Davis, who recently married sailor Joe Davis. Also on base is Daniel Lewis, the inventor of a valuable thermostat. During the show, Joe and Gloria sneak into a warehouse to be alone. There they discover Lewis' body with two knives in it. As Joe goes for help, he is knocked out by a man who then flees. Joe hides Gloria in Petty Officer Thomas' empty tent and returns to his post. When the authorities examine Lewis' body, they discover he was killed by a blow to the head and that the knife wounds are the result of torture. Later, they arrest the Rajah, who was trying to escape. Then, finding a button on the floor, they search for a sailor with a missing button, and Joe and Gloria are brought in for questioning. Soon, Capt. Dave Towne arrives to head the investigation. He recognizes the Rajah as Gordon Shane, who was convicted by evidence given by Lewis during a court-martial. The Rajah admits that he had reason to kill Lewis, but insists that Lewis was dead when he entered the warehouse. His guilt seems certain, however, when he is shown to be wearing a ring that matches the cut on Joe's chin. The Rajah is charged with the murder and given into the custody of First Officer Barnes. On the way to the holding cell, Barnes says sympathetically that he believes the Rajah's story and will allow him to escape. Then Gloria accuses Barnes of Lewis' murder, saying that she saw him enter his tent during the show and change his clothes. Barnes knocks Gloria unconscious, but the Rajah stops him at gunpoint. A shootout ensues, and the shots attract the others. Towne reveals that Barnes was trying to steal the thermostat for the Nazis and used the Rajah to set a trap for him. The mystery wrapped up, Joe is given thirty days leave to continue his honeymoon with Gloria.
