A couple of weeks ago Humphry Knipe got in touch to put me right about an astrological incident of the early Roman empire. He kindly sent me a copy of his novel, which concerns another Roman incident, the death of Nero and the involvement of his freedman Epaphroditus, in the context of an almost universal belief in astrology.
Knipe has done the technical research well; by use of the astrological techniques of the day he has worked out what precisely Nero and his contemporaries would have been concerned about, while making it clear (through Epaphroditus, the narrator) that he doesn't believe a word of it himself. I'm particularly interested, because of my own long-ago researches around Eleanor of Aquitaine, that Knipe believes two horoscopes provided by the second-century astrologer Vettius Valens are in fact those cast for the times of Nero's birth and death.
My knowledge of classical times, other than astrology, is sufficiently sketchy that I did not notice any errors of detail, and the scene-setting (starting in Alexandria, then mostly in and around Rome) is convincing. The characterisation of Nero and his mother Agrippina is pretty vivid. Though I was left a bit unsure about the role in events played by early Christians (Saints Peter and Mark make several personal appearances).
Anyway, if you want a bit more ancient science with your Roman fiction than you get from Lindsey Davis, Robert Graves or Suetonius, you'll find it here.