From the Foreword:
The sandmen and their etoile masters have proved to be one of the most enduring menaces of the Dark•Matter setting - insidious, organised and ruthless. They threaten heroes not only with violence and death, but with transformation into agents of unbound machines from an unknown time and dimension.
The idea of a fan-written expansion on the sandmen, along with other major creatures of Dark.Matter, arose from the Dark•Matter mailing list in February 2002. Besides the material written for this project by James Nostack, David Tormsen and myself, the collection includes references from mailing lists, online chats and games that provided more clues to what the sandmen might be and how they operate. This work doesn't promote a new interpretation of what's gone before, but rather, many theories and directions from which to choose.