An unprecedented powerful virus swept the entire country. The consequence of an accident full of doubts was that everyone at the scene died after a 2-day incubation period, with a mortality rate of 100%! In order to deal with this mysterious virus, a "Special Infectious Disease Prevention and Control Team" was established to find a solution and investigate the truth behind it. During the investigation, Li Mingxian (played by Yan Jijun), a member of the team, felt that the virus incident was far from as simple as imagined. At this time, they discovered that there was a survivor at the scene at the time. In order to prevent more people from being infected, Mingxian had been tracking the survivor Jin Renzhe (played by Kim Hyun-woo). So a cat-and-mouse game began, and Mingxian was suspected of being infected with the virus during the tracking process. Faced with an increasingly harsh environment, what is the final truth...