After graduating from Midshipman's school, Ensign Willis Seward Keith is assigned to the USS Caine a decrepit, 20-year old converted ship equipped for mine sweeping. The officers of the Caine include the Exec, Lt. Steve Maryk and the Communications officer, Lt. Tom Keefer. Willie's not too impressed with the ship's Captain and is pleased when he learns that they are to get a new commanding officer in the form of Lt. Cdmr. Philip F. Queeg. Queeg is an odd duck whose leadership skills are sorely tested. Tom Keefer takes a dislike to him and plants in Steve Maryk's mind the idea that Queeg may be mentally unbalanced. It all comes to a head in a typhoon when Merrick puts Queeg on the sick list, leading to his court-martial where he is defended by a very able lawyer, Barney Greenwald.