Fervor and devotion drive millions of the Emperor's loyal subjects to go on pilgrimage each year. One of the most visited Sanctuary worlds in the galaxy is Lubentina, famous for housing the holy relics of Vadok Singh, the War Mason of the Imperium. But while rumors of the appearance of six-limbed creatures agitate the people, the battle sisters of the Adepta Sororitas responsible for protecting the holy cathedral will be confronted with threats much more dangerous than a simple rebellion...