Gliwensbourg, winter 1915, a French trench is pounded, all the soldiers are buried making only one survivor. Underground, the soldier who survived managed to get out of an air pocket and crawl into a hole leading to a mysterious tunnel.
The arrival of a prefectural census-taker in Gliwensbourg threatens to compromise the secret that unites the clans. A plan takes shape, Ma decides on a "Hungarian-style exquisite corpse", but nothing goes according to plan.
