Geum-Ja (Yeong-ae Lee) is framed for a child murder by the child killer.
Geum-Ja plots revenge during her 13 and 1/2 year prison sentence.
After being released, she uses her prison buddies to locate and abduct the child killer. She then discovers that he killed another 3 children.
She presents the evidence to the families of the victims, and they all participate in the child killers grisly execution.
Thanks Don P!