Billy Boyle, a young Irish-American cop from Boston, has just been made detective when WWII breaks out. His 'Uncle Ike' (Dwight D. Eisenhower) has been plucked from obscurity to command Army forces in Europe and he wants Billy to be his personal investigator. But Billy, who has never left Boston before, is not sure of his ability as a detective. Dutifully, he sets off for England's Beardsley Hall. Accompanied by an aristocratic Polish officer and a beautiful British nurse, Billy's mission is to catch a spy who may have been planted there...