The Calamitous Crusade

At the turn of the 42nd Millennium, a warlord of the Traitorous Dark Angels rallied together warlords from two other legions to form a combined force to assault the fortress world of Brigannion IV. Answering a call for aid, a young hero of the Sons of Horus, rushes to the fortress world with his forces as they ready for a crusade, the likes of which hasn't been seen in millennia.