Toby O'Dare, a contract killer of underground fame is on assignment to kill once again. Into O'Dare's nightmarish world of lone and lethal missions comes a mysterious stranger, a seraph, who offers him a chance to save rather than destroy lives. O'Dare, who long ago dreamt of being a priest but instead came to embody danger and violence, seizes his chance.

Toby O'Dare, former government assassin, is summoned by the angel Malchiah to fifteenth-century Rome--the city of Michelangelo and Raphael, of Leo X and the Holy Inquisition--to solve a terrible crime of poisoning and to uncover the secrets of an earthbound restless spirit, a diabolical dybbuk.