When a crop of doped-up athletes from the Lakecrest College swim team dive into the campus lake to blow off some steam, the bloodsucking leeches below the surface undergo a stunning transformation. After ingesting small amounts of the swimmers' steroid-laced blood, the slimy creatures grow to unusual sizes and set out to sink their teeth into an unsuspecting student population.

Eighteen year-old Corey Peterson and his mother move to a small town due to a trauma in their past. On Corey's first day at Hallows End High School, he's approached by Mason, also new in town, who tells him about the death of his friend at the school and advises Corey to stay away from the wrestler Perry and his gang. When two other students vanish, Corey decides to talk to Principal Rizcheck, who pays no attention to him. Corey and Mason investigate the secret about the school and expose the dark truth about Hallows End and the missing students.

John, a new student at an exclusive private school, is having trouble with a group of bullying jocks who are jealous of his friendship with beautiful classmate Mary. He's intrigued, then, when enigmatic misfit Luc offers him a chance to get back at them using witchcraft - but doesn't realise that the price of his new-found power may be his life.