An oceanologist born in Venice returns to his hometown because he was summoned there by an elderly colleague of international fame. When he arrives in the lagoon, the man does not find his colleague, so he sets off in search of him risking his life several times.
| Actor | Role |
|---|---|
 Giuseppe PambieriProf. Marino Magnolato | Prof. Marino Magnolato |
| FFrancesco CarneluttiProf. Maniago | Prof. Maniago |
 Didi PeregoContessa Vandeani | Contessa Vandeani |
 Rada RassimovAnna Magnolato | Anna Magnolato |
 Anna Maria GuarnieriBetty Cadorin | Betty Cadorin |
 Matthias HabichProf. Eric Vansee | Prof. Eric Vansee |
 Pietro BiondiTrevisan | Trevisan |
 Renato MoriCommissario Anzani | Commissario Anzani |