Commissar Colonel Ibram Gaunt and his Tanith First-and-Only must protect the temple world in the Sabbat system, vital to the spiritual resilience of the Imperial forces. But the minions of Chaos have their own designs on this prize and will stop at nothing to seize it for their dark gods. Fighting for sacred Hagia, Gaunt and his men must save what makes this planet so important to the Imperium: the remains of Saint Sabbat herself, a warrior of ancient times who defended an entire star system for humanity. But it remains to be seen who will save whom on this desperate pilgrimage...