After serving in Europe during World War II, Herbie Brown (Lou Costello) and Slicker Smith (Bud Abbott) return to the United States aboard a troop ship. Also on board is their old nemesis, Sgt. Collins (Nat Pendleton). As the ship nears New York, Collins and his superiors search the men's belongings for contraband. Herbie accidentally activates a time bomb, made to look like a camera, that he picked up as a souvenir and has to throw it out the porthole.