Seung-a, who has lived a life that is moderately conscientious and moderately selfish, conforms to reality. A tragic event occurs when her beloved younger sister, whom she cherished more than her own life, dies in a traffic accident right before her eyes, and from that moment, Seung-a's life crumbles miserably. Tormented by her anger towards the world and guilt over her sister, a headhunter from the human trash disposal group 'Scorpion's Time' appears before her. With nothing left to lose, Seung-a accepts her proposal and joins the organization... While living a double life, working part-time at a bookstore during the day and eliminating criminals at night, two women suddenly appear before Seung-a, pulling her into an uncontrollable whirlwind once again.