Michel Constantin

Set in Europe during WWII, a group of American soldiers on their way to military prison are beset upon by a German artillery attack, escaping with Switzerland in their sights. Before making it any farther, they volunteer to steal a V2 warhead for the French Underground - taking them deep into the heart of German territory.

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.