The Battle of Passchendaele, 1917. At the start of a pivotal allied offensive, the nine-man crew of a British MKIV Tank set out on a mission 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.

Determined not to perish amongst the fetid mud and poison smog of the battlefield, the crew refuses to resign to its fate, and instead rallies together to fight for survival against seemingly insurmountable odds.