A brilliant Alliance geneticist who disappeared years ago walks into a police station in Siberia wearing a hazmat suit and claims to be responsible for the deaths of his wife and three children. But before he can be questioned, he is kidnapped by his former employer, Gai Dong Jing, an ex-Alliance officer who is head of a terrorist network conducting bioweapon research of deadly proportions.

With the threat of a worldwide epidemic looming, Sydney and the APO team must locate Jing and decode the toxic scientist's medical diary, which holds the answers to the virus he carries and the fate of the scientist's family. In the meantime, the highly contagious geneticist plans to rid himself of his illness in the most unimaginable way...