Technology is advancing, and human greed has no end. In order to become the most powerful, the research of biological and chemical weapons has become the subject of secret development competitions among various countries. However, the failure of a state-of-the-art biological and chemical weapons experiment brought unimaginable disaster to the world. No one expected that the virus that could be controlled in the laboratory would mutate uncontrollably the moment it came into contact with the outside air. This caught the developers' surprise and turned them into their first batch of test subjects. The mutated virus swept the world in the air, and in less than a month, the world was in a state of chaos. The global population of 7 billion has rapidly dropped to less than 10 million. The remaining survivors are not only facing the loss of their former kind, but also the competition for survival resources among various survivor bases.