A handsome, enigmatic stranger (Terence Stamp) arrives at a bourgeois household in Milan and successfully seduces each family member, not forgetting the maid. Then, as abruptly and mysteriously as he arrive, he departs. Unable to endure the void left in their lives, the father (Massimo Girotti) hands over his factory to the workers, the son abandons his vocation as a painter, the mother (Silvana Mangano) abandons herself to random sexual encounters, and the daughter sinks into catatonia. The maid (Laura Betti), however, becomes a saint.