A psychotic mother encourages her children to torture the new inhabitants of their former residence. After a bank robbery has gone wrong, three brothers on the run from the law head for home, only to discover that their mother lost the house in a foreclosure. The new owners and their guests, gathered for an ill-timed birthday party, become the brothers' unwitting hostages. Their mother and sister arrive, and it soon becomes obvious that Mother will do absolutely anything to protect her children.