September 314AD and once more murder strikes the sprawling streets of imperial Rome. When two prostitutes are found viciously murdered, it is feared that the notorious killer Nefandus has returned. Rumoured to be an imperial officer, he once waged bloody murder amongst Rome's prostitutes but disappeared before his identity could be discovered. Has the killer really returned, or is someone working in his guise?Desperate to retain order, the Empress Helena turns to her most trusted agent, Claudia. Helena commands her to discover the true identity of the Nefandus, and bring the killing spree to an end before Rome descends further into murder and mayhem.