The strain of war on relationships is the terrain Carol Reed explores in this grim WWII drama. The Key stars Sophia Loren as Stella, a young Swiss woman whose grief over the death of her fiancé has led her to offer herself to a string of others who share his dangerous profession. Like Chris Ford (Trevor Howard), her current lover, he captained a tugboat that patrolled U-boat lanes, rescuing damaged cargo ships. Believing that his number also will soon be up, Ford gives Stella's apartment key to his friend David Ross (William Holden), another tug captain, only recently arrived in England. After Ford's death, Ross overcomes his initial reluctance and makes use of the key. Stella is touched by Ross's vulnerability, and the two quickly fall in love. But, given her past, Ross is still not entirely sure of her love. Eventually he must take on an extremely perilous assignment from which he believes he won't return and must decide whether to pass the key along to another man. The Keyis a complicated, rewarding film, most notable perhaps for its gritty, exciting scenes of naval rescue.