Scribe IV is an obsolete automaton living on the Bastion, a secluded monastery in an abandoned corner of the galaxy. When the visiting Pope is found murdered, Scribe IV knows he has very little time before the terrifying Sisters of the Drowned Deep rise up to punish all the Bastion?s residents for their supposed crime. Quin, a recovering drug addict turned private investigator, agrees to take the case. Traumatized by a bizarre experience in his childhood, Quin repeatedly feeds his memories to his lover, the angel Murmuration. But fragmented glimpses of an otherworldly horror he calls the crawling dark continue to haunt his dreams. Meanwhile in heaven, an angel named Angel hears Scribe IV?s prayer. Intrigued by the idea of solving a crime with mortals, xe descends to offer xyr divine assistance. With the Drowned Sisters closing in, Scribe IV, Quin, and Angel race to find out who really murdered the Pope, and why. Quin?s missing memories may hold the key to the case ? but is remembering worth what it will cost him?