September 314 AD and in the Caelian quarter of Rome the Nefandus has reappeared. For years he waged murder throughout Rome, killing prositutes from the house of Isis. He only ceased his brutal slayings when Constantine became Emperor. Now he has returned and already two young women have been barbarously slain. Then Attius Enobarbus, henchman of the former Emperor, is found stabbed to death at his villa. The Empress Helena turns to her most trusted agent, Claudia, to enter this arena of blood. Could these events be connected and will Claudia find the murderers before Rome descends into mayhem?