The Warp, also called the Immaterium, the Empyrean, or simply the Sea of Souls, is a boundless parallel dimension underlying the material universe. It is not a place of stars and vacuum but an ocean of raw psychic energy, its tides shaped by the fears, hopes, hatreds, and dreams of every sentient creature in realspace. Where mortal emotion pools deepest, it congeals into gods.
From this churning maelstrom the four Ruinous Powers of Chaos were born, and with them the endless legions of Chaos Daemons that swim its currents like predators in a lightless deep. To gaze upon the Warp unshielded is to invite madness; to sail it is to risk the soul. Yet humanity depends upon it utterly, for only by translating vessels into the Immaterium can starships cross the impossible gulfs between worlds.
The boundary between the Warp and reality is thin, and in places it tears entirely. Through such wounds pour the daemon hosts and the corrupted warbands of the Chaos Space Marines, who make their lairs within the storm. Time and distance mean nothing here; a voyage of a day may cast a ship a century astray, or wreck it upon shoals that exist only in nightmare. The Warp is at once the Imperium's greatest highway and its most ancient terror, the source of every psyker's power and the doom that stalks them all.
The star-charts continue
