Mordian System

The Mordian System is a Stygius Sector hive well whose principal world is tidally locked: one face baked, the other in permanent night, and all the people crammed into the dark. The Tetrarchy rations everything; the Iron Guard is what stops the hives tearing themselves apart.

Chaos has tried the night side more than once, from a summoned invasion to the Stygius war and a later Webway rupture. Sister worlds Dawn, Luminaria, Nigrellum, Obfuscane, Rho-Delpha, Sanor's Fall, and Vander's Landing share the charted well.

The Mordian System still matters as the Iron Guard's home star. Unofficial maps keep the Stygius parent.