A doctoral candidate working in the British Library discovers a centuries-old volume containing the secrets of the Knights Hospitallers, one of the military orders of warrior monks who participated in the Crusades and established a hospital in Jerusalem for the healing of injured pilgrims and crusaders. Embedded in that codex is a piece of parchment—a written confession—that has the potential to turn the world of Christianity on its end. Following the discovery, a series of murders-including that of the graduate student, begin to take place in New York City—all mysteriously related to the Knights Hospitallers. Deputy Chief Mag Goldman of the NYPD calls upon his friend, Professor Bradley Davison, of Queens College to assist him in deciphering clues and evidence found at the crime scene. Once again, Brad Davison is drawn into an investigation that baffles the police in their attempt to track down the serial killer and the secrets of the Hospitaller Codex.