On Hallowe’en night most of Sunnydale’s youth were out trick-or-treating in costumes rented from a new shop owned by Ethan Rayne. Unbeknownst to them Ethan had cursed the costumes, so that the wearer would assume the characteristics suggested by their attire. Chaos ensued, before Giles interceded.
Ethan and Giles had met shortly after Giles dropped out of university, and became part of a group who dabbled in the black arts. They eventually succeeded in summoning a demon, Eyghon, but things got out of control, and the group was forced to kill one of their members who had become possessed. Eyghon and Ethan were reunited in "The Dark Age", and both were defeated by Buffy. Ethan was engaged by the Mayor and Mr Trick to divert attention from their own plot in "Band Candy", which he did by supplying the town’s citizens with chocolate bars that regressed them to their adolescent state.