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.
In a strange and isolated chateau, a man becomes acquainted with a woman and insists that they have met before.
An ambitious mobster plans an elaborate diamond heist while seducing the daughter-in-law of a ruthless mob patriarch as a determined police commissioner closes in on all of them.
