In the Qinling Mountains of Shaanxi, it is rumored that Fusu, the son of Qin Shihuang, died here during the Qin and Han Dynasties. On this day, Tang Zeng, who was working as a tour guide, took his girlfriend Chenxi and friend Tang Xiaowei back to their hometown to play. On the long-distance bus, they met Luo Ping and Mai Jiaqi, who claimed to be engaged in environmental protection research, and the hospitable Tang Zeng agreed to serve as tour guides for them. The journey seemed destined to be fr...