It's spring, the daffodils are blooming, and the kids at East Moulton High are all revving up for their May Day prom. But Betty Trenka, temping in the principal's office, feels uneasy. If only the other kids didn't pick so often on fourteen-year-old Tommy Rockwell, who already takes too much grief from his divorced parents. If only Tommy wasn't so friendly with sinister odd-job man Brad Melville and Brad's witchy soulmate, Raven. As hidden forces gather strength around her, Betty's uneasiness turns to dread - and the horror looming over the May Day festivities in the high school gym begins its inexorable unfolding.