Address Unknown

Martin Schulz and Max Eisenstein are German expatriate art dealers living in the United States. Their families are close, and Martin's son Heinrich and Max's daughter Griselle are in love. When opportunities arise, Griselle accompanies the family back to Germany to pursue acting opportunities.

The families travel back to Germany to seek artwork and pursue Griselle's acting career in Europe. Griselle accompanies them, setting the stage for the political and cultural upheaval to come.

Martin meets Baron von Freische and is drawn into the Nazi Party. He rises to a significant government post, aligning his career with the regime. This change drives a growing rift between Martin and Max, who remains sympathetic to his Jewish friend.

Martin insists that Max stop writing to him because of his new political position. Max sends a hand delivered letter to confirm that he is not acting under duress. Martin makes it clear they are no longer friends.

Griselle, who had been acting in Vienna under the stage name Stone, lands a leading role in a Berlin production. The censor demands lines be cut to fit Nazi doctrine. Her rising profile brings her into direct contact with political controls on art.

On opening night Griselle speaks the lines despite censorship. The censor exposes her true identity, triggering an antisemitic riot in the theatre. The director manages to extract Griselle to safety.

Griselle seeks refuge from Martin at his country estate after the riot. Martin refuses to help, slamming the door in her face. The situation escalates as gunshots are heard at the property.

Max and Heinrich receive a brief letter from Martin stating that Griselle is dead. The tragedy underscores how far the alliances have eroded under Nazi pressure. The loss reverberates through the families.

Martin gets a telegram saying Max will resume writing and that he will understand the messages. He soon discovers Max's first letter is coded, and he is warned that receiving coded messages is illegal. As a result, he is forced to resign his party position.

Elsa moves the children toward Switzerland for safety. Martin sends a letter asking Max to stop writing, but border guards see it and Elsa destroys it to shield the family. The episode heightens the scrutiny on Martin and his circle.

Von Freische pressures Martin to name his associates. Martin maintains his innocence, but the threat of the Gestapo looms large. He contemplates suicide and, that night, leaves his mansion with a guiding flashlight.

Back in San Francisco, a letter addressed to Martin arrives and is stamped Address Unknown. Max realizes he had not resumed writing to his father, and Heinrich's reaction in a later scene reveals that it was he who was sending the letters all along.