Early in his naval career, Ken White (William Holden) is suddenly given command of his submarine, the USS Tiger Shark. To keep from being sunk, he orders a dive while the captain and another crewman are outside, and both are killed. White is promoted, but the events on the Tiger Shark continue to haunt him and also disrupt his marriage. Eventually, White takes a desk job. But when the Korean War flares up, White is called back to active duty and asked to lead the Tiger Shark once more.