In a parody of the Harry Potter series, Grim sends Billy and Mandy to a sorcery school so the latter duo could avoid boring summer camps they were supposed to go to. The sorcery school is owned by Dean Toadblatt, an anthropomorphic frog. Billy and Mandy are sent to the most hated house on the school, Weaselthorpe, while Grim becomes a prefect for a more loved house, Gunderstank. Billy and Mandy then team up with boy wizard Nigel Planter to sabotage Gunderstank. During the episode, Planter takes all the credit for the sabotage (which was Mandy's idea in the first place), but in the end, he is punished for it once he is "accidentally" found out by Toadblatt.