A story focusing on a conflict between a People's Liberation Army squad and a bandit gang in north-east China during the Chinese revolution.

The story starts because of one journey. Seven people who have never met before climb aboard the same ride that goes into a seemingly endless tunnel. Despite the countless trials, corpses that mysteriously appear, past acquaintances that returned from the dead and an unseen danger threatening to swallow them whole, it's as if they are trapped in an enclosed space where there is no escape.