Steve and his friends find that their usual table in the school cafeteria has been usurped by a new clique. When they face being beaten up by jocks, they split up. Steve takes refuge in a curiosities shop run by a persona of Roger and discovers a book of witchcraft. Despite Roger's warnings not to touch the book, Steve is drawn to it when it magically writes his name inside and takes it to his friends where they decide to give it a shot. They successfully get their table back, although Principal Lewis, a witch hunter, senses their new power and keeps tabs on them.
Meanwhile, Hayley and Francine decide her funnel cakes are good enough to sell, while Klaus reviews 90s bands for an upcoming festival. Stan blows it off at first, but soon becomes Klaus' partner. The boys, testing the book further after their original success, decide to avoid the evil "blood magic" spells after becoming frightened by a partial incantation and use only the good magic.
Steve decides to improve on his lunch seating placement by trying to mingle in with the jocks but is rebuffed, so he uses blood magic to turn the top jock into his personal zombie. When his friends try to stop him, he turns the zombie loose on them and sets out to enslave the entire town. Principal Lewis kills the zombie, and Snot and the others go to the curiosities shop hoping to get help before he can kill Steve. Roger is unaware at first that his book is missing, but they deduce that Steve is at the 90s band festival as part of his plan to enslave everyone.
They arrive and Roger notes that Hayley and Francine have turned their funnel cakes project into a concession stand and gets in line to support them. As the boys search for Steve, they discover him hiding backstage where he kills the lead singer of Semisonic and some audience members. Snot, Toshi and Barry attempt to stop him but their battle is a draw as Principal Lewis takes aim at Steve with his crossbow, but is felled by Roger, annoyed that he cut in front of him in the funnel cake line. Lewis still tries to take a shot, but it is deflected by Steve and kills Barry. With their power unstable, the magic clashes and causes an explosion, which brings Steve back to his senses. While distraught over the death of Barry, Roger reveals that the spell book does have an 'undo' spell, but only agrees to let Steve use it if he buys a pewter dragon figure from Roger. Barry and everything is restored as before the boys discovered magic but they find themselves without a table again. Steve gets an idea to have something that bonds them together in an identifiable way, and after they all get beaten up by the jocks, they have their own group again.