World War II is drawing to a close. Despite desperate resistance, the Allies are advancing on Berlin and getting ready for the final push. Meanwhile, a small group of German soldiers is being driven to the front, when they fall into an ambush, venture deep into a forest on foot, and seek refuge in an abandoned bunker. As they soon discover, however, the dark recesses of the bunker are full of secrets, and now, they must struggle to stay sane in the face of horrors much worse than anything the war has to offer.