Arthur Penhalion.

Arthur Penhalion is a 12-year-old boy who has been named the Rightful Heir to the Architect in the House. He is reluctant to accept the position and is not well informed as to what he is supposed to do as the Heir. Arthur must fight the Morrow Days in order to recover the seven Keys and seven parts of the Will of the Architect. He must also try to figure out the new world he is experiencing. Arthur is a mortal from a Secondary Realm. However, the more he uses the Keys, the closer he comes to being an immortal Denizen and permanent resident of the House.

Leaf.

Leaf is a girl who is about Arthur's age. She is from the same Secondary Realm as Arthur. Leaf has a brother, Ed, and is a brave girl who wants to help Arthur save the Secondary Realm. They have...