The tale is set in Ancient Rome and opens in September AD 89, immediately after the previous novel The Graveyard of the Hesperides closes (Flavia's husband having been struck by lightning during their wedding celebration).[5]
The story revolves around the third Pseudo-Nero, who had the support of the Parthians. Falco and Helena, Albia's adoptive parents, are mentioned but do not appear. The plot also involves a vicious white cat, a war elephant, a military archive, cataphracts and several references to public toilets including "the event which would supersede everything else when the Daily Gazette wrote up today's events".[6]
The UK paperback cover image is of a two-faced Janus head from Vulci.[5]