In 1916, from July to November, the Battle of the Somme takes place. Within the first hours, 20,000 British soldiers were killed. A strategic plan is then developed to destroy the enemy front. A huge bomb is to be placed in a specially constructed tunnel, 100 feet below no man's land. To implement this, the soldiers must rely on the assistance of civilian miners. Four weeks and only one attempt remain until the all-important day.