Responding to Scott's howl, the alpha savages Derek and traps Scott and Stiles in their high school. Events escalate even further when Allison, Jackson and Lydia are lured to the school as well with a phony text message.

Jackson discovers that he has aconite poisoning and thinks he has figured out what is up with Scott. Meanwhile, Derek hides from the manhunt in Stiles' room while Stiles and Scott try to get Allison's necklace and any clues that may lead to the identity of the alpha. Teammate Danny lends Stiles his internet expertise to help in the search.