The Battle of Passchendaele, 1917. For three years the great war has been waging, and the two armies find themselves entrenched along the four-hundred-mile Western Front. At the start of a pivotal allied offensive to break the stalemate, the nine-man crew of a British MKIV Tank set out to destroy a series of heavily defended German bunkers.

Advancing across no-man’s-land under intense enemy fire, all seems lost when the tank becomes trapped in a giant shell crater, within only a few yards of enemy lines. However, determined not to perish amongst the fetid mud and poison smog of the battlefield, the soldiers refuse to resign themselves to their fate. Instead, the men rally together to fight for survival against starvation, shellshock, and relentless gunfire.