Mateo Castile's life has not been easy since he became a priest. Recent decades in Mexico have been wracked with instability and conflict. Father Mateo struggled to balance his faith with the pragmatic concerns of preaching when the law told him he must not. But this is not what has assaulted Mateo's faith at its core. The nearby murders and kidnappings were not politically motivated, as he had suspected. A gruesome and horrid cult thrives at the heart of the brewing war. How, Mateo wonders, could a kind and loving God allow what he saw that night to exist?