Sweet teenage girl Mary Horowitz (a fine and sympathetic portrayal by Susie Duecker) witnesses her family being brutally slaughtered. She's put in a psychiatric ward for protection. However, Mary figures out that there was more to the massacre of her family than meets the eye and thus transforms herself into an evil supernatural entity known as Mary Horror in order to exact a harsh revenge on everyone who's wronged her. Writer/director Ryan Scott Weber relates the gripping story at a cracking pace, does an expert job of creating and sustaining a strong mood of profoundly unsettling dread, offers a vivid evocation of the sleepy small town setting, delivers several satisfying moments of in-your-face graphic gore, and pulls out the stirring stops in the harrowing second half in which Mary embarks on a ferocious rampage. The sturdy acting by the bang-up cast keeps the picture humming, with especially praiseworthy contributions by Joe Parascand as evil no-count Sheriff Tom Walker, Tazio Ruffilo as Mary's unfaithful jock boyfriend Mark Silva, Joseph Sgro as the corrupt Mayor Grafton, Katie Farley as sexy cheerleader Kim Fines, and Therese Crowley as Mary's concerned mother Therese. Popping up in fun cameos are Shawn C. Phillips as foul-mouthed grave digger Andy Riley, M. Kelley as Andy's laid-back buddy Paul Rogers, Patricia Quinn as wise fortune teller Madam Ruth, Troma head honcho Lloyd Kaufman as himself, and, in a witty fleeting bit, Ernie Hudson of "Ghost Busters" fame. Moreover, this movie earns extra points for presenting adolescent characters that look, act, and talk like real teenagers as well as taking the time to carefully establish Mary as a tragic and pitiable character who's forced by terrible circumstances beyond her control to ultimately become a frightening monstrous figure. Ryan Coyle's sharp cinematography gives the movie an impressively polished and atmospheric look (the occasional use of elegant fades and dissolves is quite tasty). Scott Vincent's shuddery score hits the ominous ooga-booga spot. A neat little fright flick.