A house? Allison: Boyd! And Boyd and Erica are dead. And... and you have to write an essay. Deaton: Just memories. Derek: Cora? Derek: Cora? Derek: He's gonna kill them. Derek: She's my sister, my younger sister. Heather? Isaac? It's been closed for years. It's, um... it's an abandoned bank, and they're keeping them locked inside, inside the vault. Peter: 'Cause Boyd and that girl aren't gonna kill each other. Stiles: Is that awful? Stiles: Is this whole, like, "remain optimistic "in the face of complete and utter disaster" thing a part of the "be a better Scott McCall" program? They're gonna kill Derek and Scott. To the place you found Erica and Boyd.
Plan: A: Stiles' childhood friend; Q: Who is Heather? A: The guys; Q: Who helps Isaac recover his memory? A: Isaac; Q: Who is the boy who helped Heather recover her memory? A: an abandoned bank vault; Q: Where were Boyd and Erica kept? A: Cora; Q: What is the name of the female werewolf that Derek recognizes as his younger sister? A: the Hale house fire; Q: When was Cora presumed to have been killed? A: 3 months; Q: How long had Boyd and Cora been kept from transforming? A: Allison; Q: Who saves Derek and Scott by setting the wolves free? A: the wolves; Q: What does Allison set free to save Derek and Scott? Summary: Stiles' childhood friend, Heather, is attacked and goes missing. The guys help Isaac recover his memory, and it is revealed that he had found Boyd and another female werewolf being kept in an abandoned bank vault. However, Erica may already have been killed. When Derek and Scott break in to save them, Derek recognizes the other female werewolf as his younger sister Cora, presumed killed in the Hale house fire. Stiles and Peter discover that Boyd and Cora had been kept from transforming for 3 months. Wild and bloodthirsty, Boyd and Cora almost kill Derek and Scott until Allison saves them by setting the wolves free.