A gang of robbers takes possession of a load of diamonds.. Only one of them, Mark Lemmon, is arrested and sentenced to life imprisonment. But before being captured, the gangster had managed to hide the loot in a sewer. Five years later, Mackenzie, an insurer, pretending to be a mafia boss, assigns three petty criminals to arrange his escape. Once free, Lemmon finds the booty but now he has to deal with his new 'partners'.
| Actor | Role |
|---|---|
 Al CliverMichael Teague | Michael Teague |
 Carole AndréNicky Stone | Nicky Stone |
 Claudine AugerMaggie Vanderberg | Maggie Vanderberg |
 William BergerMackenzie | Mackenzie |
| FFrancesco CasarettiNot listed | Not listed |
| FFrank DerosaNick | Nick |
 Tony Di MitriDr. Alfred Houseman | Dr. Alfred Houseman |
 Mariangela GiordanoSandro's lover | Sandro's lover |
 Edmund PurdomProfessor Vanderberg | Professor Vanderberg |
 Gabriele TintiSandro Vincenzoni | Sandro Vincenzoni |
 Fausto TozziMark Lemmon | Mark Lemmon |