各地再次出现各种杀人案，追查结果都指向了已经在系列第三部中去世的竖锯老怪约翰·克莱默，究竟是本尊回归，还是有党徒在模仿他的手法作案？警方一筹莫展。。。。

　　When recent college graduate Manny has trouble making ends meet, his father-in-law offers him a job evicting delinquent tenants. Manny soon finds himself unleashing a karma demon which stalks him at every turn.