He crawled down to the foot of the bunk and opened his footlocker, and took out the thick sheaf of letters that he had received from Rosa after his enlistment at the end of 1941. The letters had followed him, irregularly but steadily, from basic training at Newport, Rhode Island, to the navy’s polar training station at Thule, Greenland, to Guantánamo Bay, Cuba, where he had spent the fall of 1943 as the Kelvinator mission was assembled.