A woman devoted to her son struggles to keep him from spending his life in prison in this drama from director Bong Joon-ho. Do-jun (Weon Bin) is a man in his mid-twenties who isn’t especially bright and is easily led. Do-jun lives with his elderly mother (Kim Hye-ja), who loves him fiercely even though she has no illusions about his abilities or his bad habits. Do-jun spends much of his spare time with Jin-tae (Jin Gu), a borderline criminal who takes advantage of Do-jun’s credulous nature, much to his mother’s annoyance. When Do-jun is arrested by police and accused of the murder of a young woman, his mother is certain he couldn’t have done it and sets out to prove her son’s innocence to police detectives, who seem more interested in closing the case than researching other possible leads. At first, mother feels certain that Jin-tae has framed her son to avoid being punished himself, but as she digs deeper she suspects the truth is more complicated.