Luo Ran (Du Chun) and his friend Ning Yu (Dai Xu) are investigating the truth behind his wife's accidental death. To track down the suspect Jiang Xue (Xu Lingyue), the two board a train bound for City C. Unexpectedly, the train derailed on the way, and more than a hundred surviving passengers mistakenly entered the deserted ruins of the city, completely losing contact with the outside world. The city is full of dangers and supplies are scarce. Survivors are dying or missing one after another. Internal and external troubles are constantly challenging people's survival limits. A real and cruel "survival competition" has quietly begun, with conspiracy, suspicion, betrayal, and complex human struggles playing out in the mysterious empty city.