The Indomitus Crusade burns on across the stars, while new threats emerge to challenge mankind's resurgence.

As the Kingdom of Iron is secured and the Primarch Reborn's thoughts turn to future salients, the Archenemy strikes back against the crusade's forces. The shrine worlds of the Golden Chain are all but broken, and only Velua remains defiant. Canoness Irinya of the Order of Our Martyred Lady and Champion Gaheris of the Black Templars hold the line, fighting against the plague-ridden cultists reducing the planet to anarchy.

While the war rages on and the true enemy makes itself known, the fate of Velua and the wider crusade may rest upon the shoulders of another of the Imperial Regent's agents: the disgraced rogue trader Katla Helvintr. Heroes rise and worlds fall, and only the light of faith will guide the warriors of the Imperium to their destiny.