When deciding to try to settle in a place far from their hometown, Shanquan and his friends only hope to experience things that are different from their routine. Everything changes when a call from a friend drags them into a series of events that are difficult for them to understand. The presence of mysterious people following them is only the beginning of all these oddities. The kidnapping of one of them makes them realize they are dealing with a dangerous group of people. Furthermore, Shanquan and his friends are flabbergasted when they find someone wandering in a secret underground passage whose entrance is in their house's backyard.