In this chapter, we learn that we can solve the problem of adding the two sides together by adding "x" and "y" , or the length of a third son side . In other words, we can add the third son's side to the first two, or we can divide the world into two parts. In this case, we're adding the third side's length up to the fourth son. We're also adding the fourth side up to a fifth son, so we've got a total of six sons. The narrator asks if anyone has heard about the weird girl going to a "crazy house" . Apparently, a neighbor told him that the girl was "nuts" and that it would be a good idea for her to go live in a crazy house. We learn that the narrator is psyched to be working with Regan and Dimitroff now that they're BFFs. He's also psyched to see that they can play chess and martial arts with each other. Regan says that he's the best thing she's ever seen all week. She also says that she doesn't like Craig at all. Regan asks if the children are there, and the narrator says that sounds like they are. They're all holding a key. Regan apologizes for what she said earlier, and says that it's "wicked things" that can be dangerous. Everyone grabs hold of the key, and Regan explains that she is from the "sunken world." She says that everything in the world has two faces, and that everything she created had two faces. She tells us that she gave herself so many faces so that she could hide her true identity. She's evil, plain, and simple, she says, and she wants to leave her alone.