Spirit-eater.

A Spirit-eater is created from Nothing by sorcery. Skinless Boy is a Spirit-eater that has been sent by the Morrow Days to imitate Arthur and destroy his family. Skinless Boy uses mold spores to infect people and take over their minds.

Seven Dials.

The Seven Dials is located in the Lower House and is run by Sneezer. The Dials enable mortals and Denizens to move through time and dimensions. The Dials are used to transport Leaf and Suzy to the Secondary Realm where Skinless Boy is infecting people.

Upper, Lower, Middle Houses.

The Upper, Lower and Middle Houses are all designed by the Architect and represent the highest realms of the Universe. Only Denizens live in the House.

Nithlings.

Nithlings are unintelligent creatures created from the Nothing. They are only allowed in the Great Maze in controlled numbers. The primary purpose of Nithlings is to help train...