Famed vigilante Paul Kersey (Charles Bronson) takes his girlfriend, Olivia (Lesley-Anne Down), out to dinner and proposes to her. She accepts but is soon assaulted by a thug (Robert Joy), causing irreparable disfigurement. The thug is an associate of Olivia’s ex-husband, mobster Tommy O’Shea (Michael Parks), who is terrorizing Olivia in an effort to discourage her from testifying against him. When the coercion gets worse, Kersey takes a ruthless stand and vows to hunt O’Shea down.