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.
Michel Constantin
Geo Cassine
Jean Keraudy
Roland Darban
Philippe Leroy
Manu Borelli
Raymond Meunier
Vossellin / Monseigneur
Marc Michel
Claude Gaspard
Jean-Paul Coquelin
Le lieutenant Grinval
André Bervil
Le directeur de la prison
Eddy Rasimi
Bouboule
Philippe Dumat
Un gardien
Albert Augier
Un gardien
Jean Becker
Un gardien
Raymond Bour
Un gardien
Lucien Camiret
Maurice Gaillardbois - Le détenu qui refuse de s'alimenter