The Cadian Gate is an area of calm space leading into and out of the massive Warp Rift called the Eye of Terror. It is located to the galactic southeast of the Eye in the Segmentum Obscurus, and is the only predictably stable way out of that maelstrom of Warp energy. It is therefore a site of frequent raids by the Forces of Chaos seeking to break through the Imperial defences in the region so that they can invade the larger Imperium of Man.