A fight between Scott and Jackson lands everyone involved in detention. Jackson transforms, injures Matt and Erica, and leaves a warning from his master. Erica has a seizure as a result of the Kanima's venom and Scott and Stiles rush her to Derek. Lydia meets the strange boy she has been seeing around, only for him to reveal himself to be a younger version of Peter Hale. Lydia realizes that the young boy was a part of her imagination and that Peter has been communicating with her via hallucination all along