Adapted from John Steinbeck's story, passengers in a lifeboat take aboard a Nazi captain.
A ship sinks, and Connie Porter (Tallulah Bankhead) is alone in a lifeboat wearing a fur coat. Kovac (John Hodiak) swims and climbs in. He pulls aboard from a raft Sparks (Hume Cronyn), Gus Smith (William Bendix), and the nurse Alice (Mary Anderson), who treats Smith's leg. The Afro-American Joe (Canada Lee), Ingrid, and a baby are rescued. They also pull in a German named Willy (Walter Slezak). Kovac wants to throw him overboard, and they argue. Ingrid says her baby died. In the morning they find that Ingrid is drowned, and they cut her loose. Ritt assigns jobs. Kovac tells Connie that she only writes about herself. They head east toward Bermuda. Connie talks to Willy in German and says he is a captain; but Kovac declares himself skipper, and others agree.
Willy says that Smith's leg has gangrene and must be amputated. Connie persuades Smith his girlfriend would want him to save his life. Smith is given brandy, gets drunk, slugs Kovac, and passes out. Nurse Alice helps Willy with the operation. Willy has a compass but denies it. They argue about the course, and Kovac agrees to follow Willy's direction. Alice tells Sparks she is in love with a married man who went to London. Sparks sees Mars and Venus and suspects they are on the wrong course. While Willy sleeps, the others ask Joe to take Willy's watch. Kovac sees it is a compass and wants to kill Willy. A storm floods the boat. They tie Smith to the mast, which breaks off.
Willy rows and sings. Connie lays next to Kovac, who tells her not to slum, resenting her diamond bracelet. Connie blames Ritt for the lost food. Kovac plays poker with wealthy Ritt and raises the stakes, and Ritt accuses him of cheating. During a brief rain they try to capture water. Smith is drinking sea water and sees that Willy has a bottle of water. While the others are asleep, Willy pushes Smith overboard. Sparks and Joe find Willy's bottle of water. Then Willy is attacked and killed by the others. Sparks asks Alice to marry him if they survive. Connie says the men have quit and offers her diamonds as fishing bait. They put one on a line and catch a fish just as Joe sees a ship. A boat from the supply ship turns back, and a battle begins. The ship goes right past the lifeboat and is blown up and sinks. Another ship approaches. A German climbs aboard, and they throw his gun in the sea.
This survival drama directed by Alfred Hitchcock was
intended as an allegory of a selfish Nazi, who knows his course,
in a struggle with diverse and democratic allies, who are unsure
of their direction.