Tae-joo, a murderer serving a life sentence in prison, is given a temporary release to save the life of a seriously ill young girl, Se-hee, who suffers from Wilson's disease and desperately needs a liver transplant. Se-hee is the daughter of Yeong-woo, an old friend of Tae-joo's who is now a police officer. Upon discovering that Se-hee's now deceased mother was his ex-wife, Tae-joo realises that he is in fact her biological father, and does everything he can to try and save her life.