Warhammer 40,000: Oaths of Damnation - Exorcists Space Marine Novel by Robbie MacNiven | Black Library Hardcover

The Exorcists are a Space Marine Chapter unlike any other. To combat the forces of Chaos, they willingly accept daemonic possession, knowing that once it is purged their shattered souls will no longer be susceptible to corruption. Those who fail the banishment trials become Broken Ones – living prisons for the terrors expelled from their brethren.
When a daemonic conspiracy sees a Broken One freed, the Exorcists dispatch their Vanguard elite, the Hexbreakers, in a desperate quest to hunt it down. But the connection between their quarry and the strike force commander, Daggan Zaidu, is more than it first appears. The Hexbreakers find themselves racing against time before their Chapter's darkest secrets are revealed to the Imperium, bringing damnation to the entire Chapter.
This gripping tale explores the mysterious Exorcists Chapter through their occult libraries, arcane rituals, and theomantic esotericism. Features intense battle sequences as the Exorcists pursue their target across war-torn Fidern IV while facing opposition from Word Bearers traitor Space Marines.