Cold, rain, and fog surround a plant in Ravenna. Factory waste pollutes local lakes; hulking anonymous ships pass or dock and raise quarantine flags. Guiliana, a housewife married to the plant manager, Ugo, is mentally ill, hiding it from her husband as best she can. She meets Zeller, an engineer en route to Patagonia to set up a factory. He pursues her, they join friends for a dinner party of sexual play, then, while Ugo is away on business, she fears that her son has polio. When she discovers the boy is faking, she goes to Zeller, panicked that no one needs her. He takes advantage of her distress, and she is again alone and ill.