A young doctor, Heo Jun, considered the best in the country for liver transplants, witnesses his beloved wife brutally murdered by an intruder in their home. He tries to fight back against the assailant but only manages to sustain a stab wound to his hand, and is instead framed for his wife's murder. Although released due to insufficient evidence, he is branded as the doctor who killed his wife, socially ostracized, and falls into despair. Since then, he drifts through the world of mixed martial arts fighting, searching for anyone with a stab wound scar on their palm. One day, he receives an offer he cannot refuse from Dongbang boss Gu Dong-man. Gu Dong-man claims there is a tape recorded by the real culprit as Heo Jun's wife was dying, and if Heo Jun successfully performs a liver transplant surgery for him, who is suffering from terminal liver disease, he will hand over the tape.