Writers: Jean Aurel (screenplay)
Jacques Becker (dialogue)
Four convicts in a French prison share a single cell. As all are incarcerated for serious crimes, including, perhaps, execution, they decide to escape and have collected materials for the purpose. Before they can begin carrying out their carefully prepared plan, another inmate is moved to their cell. What now? They have no choice but to tell him what they intend to do. He becomes an accomplice, and all five begin the laborious and very clever process of digging their way through the concrete floor to access underground tunnels beneath the prison and, eventually, the sewers to which those tunnels are connected.