A certain train with sleeping accommodation starts from a central Polish town long before sunset and arrives at a beach resort on the following morning. During the journey a dramatic event takes place in two compartments, Marthe and her estranged sweetheart Staszek are involved; so are a surgeon with a secret, who hides behind dark glasses; a young woman with her elderly dull husband; and finally, a murderer.

The narrative confines itself to the few hours of travel, without seeming in any way restricted. Scenes are played in deep focus along the length of the sleeping car and there develops a counter-point between the countryside seen through the windows and the scenes within the coaches—a contrast of vast, moving landscape to stuffy, crowded interiors. The ingredients add up to a thrilling journey—incidents amusing, pathetic and strange follow each other in bewildering succession. The atmosphere is one of intense expectancy, culminating in the pursuit of the killer and an aftermath of exhaustion and shame.