Into the Wild Black Yonder.
Koronus Expanse of the Halo Stars
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.