Thirteen years after the "Lawnmower Killer" killed her sister, high school student Mary Graves and obsessed detective Dick Harbinger are on the lookout for the killer to reappear during the annual Halloween Pumpkin Prom.
After several people and a dog are found dead in their closets a "mild-mannered" reporter, a college professor, her son and a befuddled professor band together to uncover the mystery but not without involving the U.S. Army and mass panic.