A rough and tumble man of the sea falls for a meek librarian.

Merchant Marine sailors Joe Rossi (Humphrey Bogart) and Steve Jarvis (Raymond Massey) are charged with getting a supply vessel to Russian allies as part of a sea convoy. When the group of ships comes under attack from a German U-boat, Rossi and Jarvis navigate through dangerous waters to evade Nazi naval forces. Though their mission across the Atlantic is extremely treacherous, they are motivated by the opportunity to strike back at the Germans, who sank one of their earlier ships.

Ambassador Joseph Davies is sent by FDR to Russia to learn about the Soviet system and returns to America as an advocate of Stalinism.

The film pivots around the local Norwegian doctor and his family. The doctor's wife (Ruth Gordon) wants to hold on to the pretence of gracious living and ignore their German occupiers. The doctor, Martin Stensgard (Walter Huston), would also prefer to stay neutral, but is torn. His brother-in-law, the wealthy owner of the local fish cannery, collaborates with the Nazis. The doctor's daughter, Karen (Ann Sheridan), is involved with the resistance and with its leader Gunnar Brogge (Errol Flynn). The doctor's son has just returned to town, having been sent down from the university, and is soon influenced by his Nazi-sympathizer uncle. Captain Koenig (Helmut Dantine), the young German commandant of the occupying garrison, whose fanatic determination to do everything by the book and spoutings about the invincibility of the Reich hides a growing fear of a local uprising.

A film of the life of the renowned musical composer, playwright, actor, dancer and singer George M. Cohan.