Billy Boyle, a young Irish-American cop from Boston, has just made detective when World War II breaks out. His "Uncle Ike" is Dwight D. Eisenhower, plucked from obscurity to command Army forces in Europe, and he wants Billy to be his personal investigator. Accompanied by an aristocratic Polish officer in exile and a beautiful British WREN, his mission is to catch a spy who may have been planted in Beardsley Hall, where the Norwegian government in exile is in residence.