Dusk is a Feral World (not quite a Death World) in the Malfian sub of the lost Calixis sector. It is a humid, swampy place, with endless jungles and mangroves, marshes and countless lakes great and small. It is a world with a fell reputation, for the veil between the realms frow thin here, and the energies of the warp are stronger on Dusk than anywhere else outside the Vortex.
Feral humans, including tribes of ogryns, have lived there since time immemorial. Dusk was added to the roll of Imperial worlds during the Angevin Crusade, but the Empire's hold over the place was always tenuous outside the few Imperial compounds. Dusk provided the Empire with a great number of psykers for a world with such a small population.
The Imperial "capital" of Asabmom was destroyed by the Red Brethren not long after the Fall of Scintilla. It was hoped the planet could provide the Chapter with recruits for the long war, for the people of Dusk have a fearsome reputation, but it was not to be. The natives had no more love for their new overlords than they did the old. Eventually, the Brethren left the world, save a small, heavily fortified, enclave in the ruins of the old capital (lest it be said they were forced to retreat).
Small enclaves of reptilian xenos live in the darkest, most hidden places of Dusk. They react poorly to intruders, but rarely attack unless provoked.
The Prophet had dealings on Dusk, it is said. Something to do with a being called the Hag and some sort of prophecy. It is possible this Hag was a xeno, no a human. It's also possible that the Prophet's dealings on the planet was what caused the Red Brethren to waste a hundred Astartes fighting over a purtid swamp.
