eun-ah was living a perfect, happy life with her family until a sociopathic young man named jae-wook brutally and senselessly murders her husband and daughter in front of her eyes. barely escaping alive herself, eun-ah is left half-paralyzed and wheelchair-bound. after her recovery, she grows fixated on taking revenge on him. two years later, following a long search, she hones in within striking distance of the killer. faced with such a dangerous adversary and her immobility, eun-ah gathers four people marginalized by society, each with a different skill, to help her kill jae-wook. in exchange, she is prepared to give them something they desperately need -- her organs. all four accomplices -- which include a north korean defector, an ex-gangster, a doctor, and an engineer -- are in need of organ transplants for various reasons, and eun-ah promises them her organs once her revenge is complete. but things don't go as planned, and the killer turns the tables and starts hunting them himself.