The path ofRoboute Guillimanand his fallen brotherMortarionbring them inexorably together onIax. Once a jewel of theImperium, thegarden worldis dying, as the plans of Mortarion to use it as a fulcrum to drag all the stellar realm ofUltramarinto the warp come to deadly fruition.

While Guilliman attempts to prevent the destruction of his kingdom, Mortarion schemes to bring his brother low with theGodblight, a disease created in the cauldron ofNurgleitself, made with the power to destroy a son of theEmperor.

Primarchsclash on the ravaged landscapes of Iax. The gods go to war, and the widergalaxybalances on a knife edge of destruction. As something powerful stirs in the sea of souls, only one thing is certain whoever wins the last great clash of thePlague War, the repercussions of victory will echo down eternity…