After his father abandons the family, Autumn Moon drops out of high school and becomes a debt collector for the Triads. On his rounds, he meets and falls in love with Ping, a daughter of one of the Triads' clients. She is suffering from a fatal kidney disease, and to pay for her medical expenses, Autumn Moon takes an assassination contract, but as he slips deeper into the criminal underworld, he's haunted by a figure from his past.