Dashiell Hammett adapted Lillian Hellman's play about a dedicated anti-fascist German visiting his wife's family in Washington.
Kurt Muller (Paul Lukas), his wife Sara (Bette Davis), and their three children enter the United States from Mexico. At the home of Fanny Farrelly (Lucile Watson) in Washington DC, Marthe (Geraldine Fitzgerald) asks her husband Teck de Brancovis (George Coulouris) not to play poker with Germans. On a train Kurt tells a sympathetic Italian that he fights Fascism. Fanny asks a colleague of her late husband to help her son-in-law find a job. She tells her son David (Donald Woods) that people are gossiping about him and Marthe. Teck plays poker with Germans. David greets his sister Sara at the train and drives them to the house where she grew up. Fanny welcomes them. Kurt says he stopped working as an engineer in 1933 in order to fight the Nazis.
Teck asks Marthe if she is in love with David. Anise (Beulah Bondi) fits a new dress for Sara. Teck gets into Kurt's briefcase and sees there is much money. Teck calls Phili von Ramme (Henry Daniell), and he tells the family he is wondering if Kurt is Max, a leader of the anti-Nazi underground. Sara tells David and Fanny that they have $23,000 for the anti-fascists, and she tells how Max saved Kurt's life. Sara suspects that Teck found out by opening the suitcase, and she says that Kurt is going back to Germany.
Teck goes to the German embassy and asks what they would pay him to turn in someone, and he is told they would pay much if the person is in Germany but nothing if he is in the USA. Kurt advises his oldest son Joshua and says why he must go. Marthe indicates she is separating from Teck because of David. Teck asks for $10,000 before he leaves. He reads aloud the history of an antifascist he thinks is Kurt, who tells him he is going to Germany but will not pay him. Fanny and David offer to pay Teck in order to save Kurt's life. After they go out to get the money, Kurt knocks down Teck and pulls a gun. While Sara is calling the airport, Kurt kills Teck. Kurt apologizes to Fanny and explains why he did it. Kurt asks David for his car and for two days before they tell the police. Kurt says goodbye to his children and admits he did something bad. Fanny and David give Kurt money for his cause. Kurt tells Sara he wants to live for her and leaves. David tells Fanny they will be in trouble, but she is proud of his courage. Joshua tells his mother Sara that he wants to go to Germany, and he is confident that she will let him go when the time comes.
This drama reflects how the Fascist war has been brought
into American homes by depicting what is considered a justifiable
homicide of a blackmailer.