Ostend railway station. Peter, an English publishing assistant, has his passport checked by officials before boarding a long-distance train. Whilst looking for his seat, he strikes up an acquaintance with Lorraine, an American woman. They discover their seats are in the same compartment.

As they discuss the nature of travelling on trains, two male passengers independently enter their compartment. They are then joined by an elderly Viennese woman, Frau Messner, who claims Peter is occupying her seat. Peter refuses to give up his seat for her. Annoyed, Frau Messner requests Peter to buy some magazines for her journey. Reluctantly he agrees, almost missing the train as it departs the station.

After a dreamy sleep, Peter awakens to discover Frau Messner has swapped seats with Lorraine and is sitting opposite him. She tells Peter she will be with him for the entire journey. Peter leaves the carriage to smoke a cigarette. In the corridor, he sees Lorraine and they renew their conversation.

The train stops at the Belgian border as police inspect passports. Peter and Lorraine witness a young man being questioned and then arrested. The train begins its journey again. Frau Messner accuses Peter of stealing her food. He rejects the allegation and exits the compartment, heading for the dining car.

Peter is astonished to discover Frau Messner following him through the train. She has been given a dinner ticket by Lorraine. In the busy dining car, Peter is obliged to share a table with Frau Messner. She vociferously criticises the service and smashes a dining plate on the floor, before storming out of the carriage. Embarrassed, Peter also exits.

The train stops at Frankfurt for a short break and Peter accompanies Frau Messner into the city for a meal. She leads them to the opera building, where they eat sparingly. She informs Peter it is her birthday the next day. She tells him stories from her past, acknowledging that her brothers were members of the Nazi party during the war.

Realising his watch has stopped, Peter rushes back to the station, only to find the platform deserted. He consoles himself, believing his train has already departed. When Frau Messner reaches the platform, Peter is furious with her. She informs him that the train has not yet left, but has merely changed platforms.

Back on the train, he searches for Lorraine. Rekindling their conversation, Lorraine tells Peter of her dislike of Europe and Europeans. Returning to the sleeping car, Peter is once again antagonised by the comments of Frau Messner.

Peter is woken suddenly during the night. The train has been stopped and he is confronted by two policemen, shining a torch in his face. After he fails to produce his rail ticket, the police question Peter over an act of vandalism to the train. His defiant stance only adds to their suspicion.

Peter is arrested and taken off the train. He attempts to bribe one of the police. He is handcuffed and thrown into a police car. Peter sees Frau Messner talking to another officer. She verifies his story and he is permitted to board the train and continue his journey.

Peter cannot believe his ordeal and angrily confronts Frau Messner. She is shocked by his aggressive behaviour. Feeling remorse, Peter looks for Frau Messner the next morning, finding her in the dining car. He reveals that it was Preston, one of the other passengers, who stole her food earlier in the journey.

Frau Messner tells Peter that today is her birthday, that she is ill and will die soon. She invites him to stay in Vienna with her. Peter declines the offer, citing his important publishing conference. Frau Messner tells Peter he only cares about himself and his work. The train pulls into Linz station. Peter disembarks and walks through the rain-soaked streets of the city.