Amenthis

Amenthis is a noctilith-rich Necron tomb world in the Maelstrom, in Ultima Segmentum, later recorded as a daemon world heavily corrupted by the warp. Millions of years after the War in Heaven it was swallowed by the storm while the Conclave of the Soulless worked upon it; the opening of the Great Rift disturbed the Maelstrom and brought the world into a freer spiral arm, incomplete in its northern hemisphere.

Its hollow interior holds a desert of wrecked starships from many species. In M42 Trazyn the Infinite led an expedition there after a repeating distress signal attributed to Sothka the Arcane, and the world proved to be under the influence of the daemon Pestamutadis the Observer.