Valentin laughs in the face of evil, gifted with the power to unmask every creature hiding behind a human face. Yet his own bloodline is far more dangerous: he was born to Satan. Left broken after an ancient war, he has spent twenty years fading without the heart his father tore away. His desperate search leads him to Isabella, a rebellious nun with a shotgun, a flask, and no patience for heavenly rules. Together, they track the Prince of Darkness while buried secrets from the long ago battle threaten to destroy them both.