"Billy Boyle, US Army detective and ex-Boston cop, faces his toughest investigation yet: infiltrating enemy lines in France as the Allies invade Normandy. It's late May 1944. Captain Billy Boyle is court-martialed on spurious charges of black market dealings. Stripped of his officer's rank, reduced to private, and sentenced to three months' hard labor, Boyle is given an opportunity: he can avoid his punishment if he goes behind enemy lines to rescue...