Here's how Toronto describes it:
Observed by their adolescent son (Seo Young-ju), a couple's fight over the husband's infidelity turns to a grotesque calamity. After failing to sever her husband's penis, the infuriated wife chooses instead to dismember her son in order to hurt his father. Family violence sparks a chain of events that culminates in a dramatic epilogue of destruction.
Take a look at the new teaser below.