With Stiles dad still missing, the teacher tells Derek that she is the only one that can save Cora and Stiles father. While evacuating the hospital, Cora’s condition becomes worse and the Twins attempts to capture the teacher. It is revealed that she was the guardian of one of them that did not kill her after all. She survived and because Derek killed Paige all those years ago, she was able to tap on a mystical power that he accidently reactivated with the human sacrifice, and she vowed to make sure these Alpha’s pay for what they did. Allison and her father arrives and Stiles discovers the true meaning of “Guardian” just as Scott also discovers the target was his mother. Deucalion, in exchange for Scott joining them, offers to help find Stiles father and his mother. He tells Stiles he has no choice and leaves with him.