Private Detective Doan, and his Great Dane -- Carstairs -- in another rambunctious roustabout when Doan is sent to the Mojave Desert to secure some property for the government. Doan poses as a Jap agent, meets up with flagwaving Harriet, finds a corpse in his car, another in his hotel room, and a third by way of glamorous Susan Sally, moving picture agent. Ends up neatly as Carstairs chews up the guilty man, a Nazi agent. Not without a certain hilarity.