Set in the 22nd century, climate change has caused the planet to become uninhabitable and humans live within a man-made shelter. A war takes place within the shelter. Jung Yi is the elite leader of the allied forces. She becomes the subject of a brain cloning experiment. The cloning experiment is a potential key to win the war.

Seo Hyun and Sang Hoon are responsible for the success of the brain cloning experiment. Seo Hyun is the team leader of the laboratory that develops brain cloning and AI technology. Sang Hoon is the director of the laboratory.