Hundreds of years ago, a meteor struck Korea and spread a microbe that devastated human life and warped living DNA. As people rushed into the orbiting city of Destiny, some of the microbes infiltrated the new community. Now, humans who are able to adapt to the microbes are known as sagents, and the microbes give them strength, intelligence, and extended lifespans. But because of those gifts, they are strictly controlled by government agencies.

Gabriel is a sagent at the start of his career, but he is already scarred by his previous agency. When he is sent on a dangerous mission to the underbelly of Destiny, everything starts to fall apart for him. Isolated from his agency and not knowing where to go, Gabriel must choose between returning to safety and Destiny, or staying and forging his own path.