The Crimson Path was the doctrine of ruin embraced by Lorgar and the Word Bearers once the Imperial Truth had failed them — the conviction that only through blood, war, and devotion to the true gods of the warp could mankind and its primarchs ascend. Where Lorgar had once preached the Emperor's divinity and been humbled for it, he now preached a darker gospel, and the road he chose ran red.
The name captured a literal creed. The Word Bearers came to believe that slaughter on a sufficient scale could tear the veil between worlds, that massacre was a form of worship and the dead a currency paid to the Ruinous Powers. It was along this path that Lorgar's Legion laboured to corrupt Horus and to kindle the great warp storms that would drown the heavens.
To walk the Crimson Path was to reject reason for faith and mercy for zeal. It made the Word Bearers the true architects of the war — not merely soldiers in a civil conflict but missionaries of damnation, spending lives without number in the certainty that their god-haunted cosmos was the only truth. Every atrocity was, to them, a sacrament.