Hierotek Circles of the Necron dynasties operate in secret throughout the stars, cold-hearted coteries of android killers acting in service to obsessive Cryptek masters. These ancient Necron techno-sages are driven by ruthless paranoia and amoral curiosity, issuing missions to their underlings according to labyrinthine plans that few outside of their own kind can understand. The Hierotek Circles employ eldritch science and specialist constructs to overwhelm all opposition, completing their clandestine missions with frightening thoroughness.