Four prison inmates have been hatching a plan to literally dig out of jail when another prisoner, Claude Gaspard, is moved into their cell. They take a risk and share their plan with the newcomer. Over the course of three days, the prisoners and friends break through the concrete floor using a bed post and begin to make their way through the sewer system -- yet their escape is anything but assured.
Elenco: Michel Constantin , Jean Keraudy , Philippe Leroy , Raymond Meunier , Marc Michel , Jean-Paul Coquelin , André Bervil , Eddy Rasimi , Philippe Dumat , Albert Augier , Jean Becker , Raymond Bour , Lucien Camiret , Durieu , Gérard Hernandez , Jean Luisi , Jean Minisini , Paul Pavel , Paul Préboist , Marcel Rouzé , Catherine Spaak , Dominique Zardi .