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.
| Actor | Role |
|---|---|
 Monica VittiClaudia | Claudia |
 Gabriele FerzettiSandro | Sandro |
 Lea MassariAnna | Anna |
 Dominique BlancharGiulia | Giulia |
 Renzo RicciAnna's Father | Anna's Father |
| JJames AddamsCorrado | Corrado |
| DDorothy De PolioloGloria Perkins | Gloria Perkins |
 Lelio LuttazziRaimondo | Raimondo |
 Giovanni PetrucciPrince Godfrey | Prince Godfrey |
 Esmeralda RuspoliPatrizia | Patrizia |
| EEnrico BolognaNot listed | Not listed |
| FFranco CiminoNot listed | Not listed |
| GGiovanni DanesiPhotographer | Photographer |
| RRita MolèNot listed | Not listed |
 Renato PinciroliZuria, the Journalist | Zuria, the Journalist |
| AAngela Tommasi Di LampedusaPrincess | Princess |
| VVincenzo TranchinaNot listed | Not listed |
 Valeria PerriMartina | Martina |
| PProf. CuccoEttore (uncredited) | Ettore (uncredited) |
| JJack O'ConnellOld Man on the Island (uncredited) | Old Man on the Island (uncredited) |