Warhammer 40k: Rimward of Terra
"It is a beast that swallows the apostate, the doubter, and all who ship with them. Better to slay the unfaithful than risk the dread Maw whilst such false wretches draw breath." —Opening lines of the Voidfarer's Warning from the Drusian Play
The Koronus Expanse is the name given by the authorities of the Imperium of Man to a dangerous unexplored region of the Halo Stars located beyond the Calixis Sector in the Segmentum Obscurus. The Expanse is accessed through the Koronus Passage, a treacherous but navigable route through the great Warp Storms that bar passage to the Halo Stars beyond the way station of Port Wander on the edge of the Expanse. As is true of the Calixis Sector itself, the Expanse was untouched by the God-Emperor’s Great Crusade many millennia ago -- and so it is a realm of fearsome xenos, treasures beyond imagining, heathen worlds of men, and the echoes of ancient doom.
For centuries, Rogue Traders have braved great evils and the treacherous warp to venture into the Koronus Expanse, but their efforts have barely begun to uncover its secrets. Footholds have been built close to the few semi-stable Warp routes into the area. Here, resource-rich worlds are exploited, xenos ruins excavated, trade envoys meet with heathen lords, and Imperial colonies are attempted upon sheltered worlds. This effort has been enough to shower wealth and fame upon the fortunate -- and make corpses of the rest. The gateway to the Expanse is littered with broken vessels and tales of the vanished.
