September 314 AD and once more death strikes the sprawling streets of Imperial Rome. When two prostitutes are found murdered - their bodies ripped open and their right eyes gouged out - it's feared a notorious killer, the Nefandus, has returned. Rumoured to be an imperial officer, he once waged bloody murder amongst Rome's prostitutes but vanished before his identity could be discovered. Has he reappeared, 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 truth behind the Nefandus, before Rome descends further into chaos and confusion.