Don Winslow of the Navy #2

Don Winslow investigates the mysterious disappearance of an official car and its driver, Eli Nordin, whose tracks vanish inexplicably in the sand at a testing ground. The story then shifts to a subplot involving Don and a nurse named Mercedes, interrupted by Don's urgent need to find Red and pursue a date. The main plot continues with Don Winslow of the Navy encountering a Nazi submarine scheme involving crossword puzzle clues sent via radio to coordinate U-boat attacks on American freighter ships in the mid-Atlantic.