Humans have been designated as invasive species in the universe. A survival game has begun, initiated by the universe's administrator to reduce the human population. In the final stage of this game, Jin Jae-hee, who has regressed, comes to one conclusion: “Kang Si-on is the only one who can lead us to victory in this game.” Kang Si-on possesses a genius-level intellect. Jin Jae-hee is a regressor who has returned to the past after losing in the survival game. With Kang Si-on as her ally, they tackle the death game using unprecedented abilities.