Mathias is professor of linguistics at a Belgian university. Although middle-aged, he is unmarried, but has a mistress, Anne. Their relationship looks as if it may be coming to an end, but Mathias tries to rekindle the flame. After a passionless dinner together, Mathias leaves to catch a train to a town where he is to give a lecture. On the train, Mathias is delighted to see Anne enter his compartment. The couple are unable to talk with one another and Mathias falls asleep. Having dreamt about a train accident, Mathias awakes to find his train has stopped and Anne has vanished. When he leaves the train to investigate, the train continues on its way, leaving Mathias and two other men stranded in open countryside.