In the early years of the Republic of China, the Institute of Biology of the Northwest Science Society received a mysterious letter, learning that there were mutant creatures infesting the sandy sea, so they sent an exploration team to the biology laboratory, but they were almost wiped out. Liu Mengxi and Xia Xuan escaped as survivors with the samples, but they met the agency in Sand Dune Town. The samples were damaged and exhausted. The two of them found that almost only old, weak, sick and disabled were left in Sand Dune Town, and outside the town, the monster seemed to have heard something and was quietly approaching Sand Dune Town...