he forces of Chaos, under the lash of Abaddon the Despoiler, have launched numerous Black Crusades from the Warp-wracked region of space known as the Eye of Terror.

Their 13th Black Crusade was the most recent and the most devastating. Uncountable hordes of Chaos Space Marines, mutants, and traitors poured out of the Eye of Terror and ravaged the defenses of the Cadian Gate. Corpses littered the battlefields in the millions after Apocalypse-scale fighting, and Abaddon managed to gain a foothold in Imperial space. With the Cadian Gate breached, the whole sector of Segmentum Obsurus faces the threat of total war.