Doctor Richard Diver is a young neurologist already gaining great respect for his work. One day, he visits his friend Franz in Zurich. Franz is treating a young American girl, Nicole Warren, who was sexually abused by her father and has suffered a breakdown. Nicole is attracted to Diver and writes him letters after he leaves the clinic. When she is almost cured, Diver returns to the clinic and decides, rather haphazardly, to marry her. Nicole comes from a wealthy family and the couple begin to travel around Europe.

They settle briefly in a cabin by the French Riviera and aim to live quietly so that Dick can finish his great treatise. Nevertheless, Dick's easy-going, giving nature attracts a band of followers. When Rosemary, a budding American film star visits their town, she too is drawn to him. She tells him she loves him but Dick remains true to Nicole.

Several years pass during which Dick still does not finish his writing and indeed does very little towards that end. Nicole suffers several relapses. When Dick runs into Rosemary again, they have an affair. Nicole also takes a lover and finally leaves Dick who has become increasingly dissolute. He drinks most of the day and does nothing.