What's a twenty-two-year-old Irish American cop who's never been out of Massachusetts before doing at Beardsley Hall, an English country house, having lunch with King Haakon of Norway? Billy Boyle himself wonders. Back home in Southie, he'd barely made detective when war was declared. Unwilling to fight--and perhaps die--for England, he was relieved when his mother wangled a job for him on the staff of a general married to her distant cousin. But the general turns out to be Dwight D. Eisenhower, whose headquarters are in London, which is undergoing the Blitz. And Uncle Ike wants Billy to be his personal investigator.

Billy is dispatched to the seat of the Norwegian government in exile. Operation Jupiter, the impending invasion of Norway, is being planned, but it is feared that there is a German spy amongst the Norwegians.

Billy doubts his own abilities, with good reason. A theft and two murders test his investigative powers, but Billy proves to be a better detective than he or anyone else expected.