Invisible predatory entities in the world of Citta'gazze that feed on the Dust (consciousness) of adults, leaving them alive but empty - breathing, eating, but devoid of will, curiosity, or awareness. Children are immune because they have not yet accumulated enough Dust. Spectres were created as an unintended consequence of the subtle knife cutting between worlds, each cut spawning a new Spectre. They are among the most disturbing creations in the series.