Li Yi, a graduate student in history, accidentally transmigrates to the Central Hebei Plain in 1942, just as the Japanese army launches its brutal May 1st Sweep. Trapped in a desperate situation, he is rescued by a mysterious veteran named Li Tieshan, who takes him into an extensive network of tunnels. In this sunless underground world, Li Yi faces hunger, injury, and the threat of death firsthand, while witnessing the astonishing ingenuity and steely resolve the Chinese people summon in their darkest hour. From a scholar who could barely hurt a fly to a fighter who takes up arms and puts his modern knowledge to use, Li Yi joins Li Tieshan, Xiuqin, Erga, and local militia members in outmaneuvering the enemy in the dark tunnels and protecting the last spark of hope with their lives. This is a struggle for survival and faith, a stirring tale of guerrilla warfare in the tunnels.
