When 16-year-old Chris Martino moves with his mother to Los Angeles from New Jersey, he inadvertently befriends nerdy classmate Roger Horseface Obst. Chris writes Roger a note in lemon juice-invisible ink-but later a different message appears, and it becomes obvious that a terrifyingly omnipotent force is about to ensnare Roger in its net of darkness. While Roger senses an opportunity for revenge against his student tormentors, Chris resists this evil presence, which identifies itself as Othersyde; therein lies the book's most forceful conflict. As the terror escalates, a policewoman and a sympathetic teacher become involved with the evil around them-and with each other.