In the near future of 2041, the COVID-19 pandemic has evolved into a virus variant with a high fatality rate. Due to an extreme shortage of vaccine supply, South Korea has been divided into the chosen and the abandoned, and the abandoned are forcibly exiled to the land of death. Ultimately, an unprecedented decision to cull survivors in the name of preventing the spread of infection is made in the land of death. Chae-young and her daughter Bani must reach the sea at the southern end within 72 hours to escape the culling. Chae-young is killed while trying to save her daughter from looters, and Joon-hyuk, who coincidentally saves Bani from human hunters, ends up being chased by Manwol's gang. Joon-hyuk and Bani narrowly escape the crisis with the help of Jae-seong and Ye-jin, but due to them, Joon-hyuk becomes infected with the virus. Meanwhile, Jae-seong, a doctor, discovers that Bani is an antibody carrier, but the amount of antibodies that can be extracted from Bani is enough for only one person. People who need Bani's antibodies to survive, Bani who must reach the sea at the southern end within the time limit – who among them will seize the last chance?