Billy Boyle, a young Irish-American, cop from Boston has just made detective - with a little help from his cop relatives and friends - when World War II breaks out.
His rabidly anti-English family calls on his mother's distant cousin, Mamie, married to a general, to wangle a staff job for him far from the fighting. But instead of a "safe, cushy" stateside assignment, he is ordered to London, still undergoing the Blitz.
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.
Billy, who had never left Boston before he enlisted and was sent to Officer Candidate School, is not sure how good a detective he really is. But when Eisenhower asks Billy to undertake this task, he dutifully sets off for Beardsley Hall, where the Norwegian government in exile, led by King Haakon, is in residence.
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 there.
A theft and two murders test Billy's investigative powers, as he comes to grips with the deadly demands of a war he never wanted any part of. To his own surprise - and that of others - Billy proves to be a better detective than any one expected.