Claudia and Anna join Anna's lover, Sandro, on a boat trip to a remote volcanic island. When Anna goes missing, a search is launched. In the meantime, Sandro and Claudia become involved in a romance despite Anna's disappearance, though the relationship suffers from guilt and tension.

• Cino del Duca
• Societé Cinématographique Lyre
• Gabriele Ferzetti
• Monica Vitti
• Lea Massari
• Dominique Blanchar
• Renzo Ricci
• James Addams
• Dorothy De Poliolo
• Lelio Luttazzi