In this thrilling, Academy Award-winning WWII drama (Best Special Effects, 1943), Tryone Power plays Navy Lieutenant Ward Stewart, a crewmember aboard a sub responsible for investigating a suspicious tanker in the Atlantic. Initially Stewart takes a liking to his commander - Dewey Connors (Dana Andrews) - until he realizes that the woman he's fallen in love with is actually Connors' fiancée. Not only that, but, once the crew tracks the tanker to an island, they discover that it's really a German Q-boat and the island is a Nazi supply base! Tension explodes as the two men must work together to defeat the enemy - and come to terms with their rivalry.