Cult of the Dragon

The Cult of the Dragon was a group within the Adeptus Mechanicus and lived on their homeworld of Mars in the Noctis Labyrinthus.

They were regarded as a group of madmen in the desolate region which they called home which was a region that other members of the Mechanicus avoided. These individuals consisted of techpriests who long ago had tried to build their Forges in the region but abandoned them; however, a few remained behind thus forming their cult.

Source

 * Mechanicum (novel)