Perfiditas is the second book in Alison Morton's Roma Nova series. I received it as a gift from the author through Book Funnel. I recently reviewed the first of the series Inceptio here. For more information about Morton's alternate universe read my review of Inceptio. I do need to tell readers that the former Karen Brown is now Roma Novan Carina Mitela and an officer in the Praetorian Guard Special Forces (PGSF).
It's the responsibility of the PGSF to protect Roma Nova from all threats foreign or domestic. In Inceptio there was a foreign threat, but in Perfiditas there is an internal threat to the matriarchy.
In order to defeat this threat, PGSF really needs Carina's unorthodox tactics, but officers who think by the book dominate the hierarchy as is typical in military organizations. This makes Carina a controversial figure similar to Captain Kirk of Star Trek. Readers who identify with Carina may be outraged on her behalf. They may think that her husband Conrad should be more supportive.
The plot is exciting. It includes suspenseful sequences of events, and reversals of fortune. It shows the fortitude of female Roma Novans from small girls to grandmothers. Perfiditas also displays the loyalty of most of the men of Roma Nova to the matriarchy.
I was pleased that men in general didn't want to see the Imperatrix overthrown, and weren't interested in collaborating with misogynistic men. During the alleged "Golden Age of Science Fiction" there were a number of matriarchal dystopias that appeared in which the men rose up against them. So I find Perfiditas a refreshing turnabout of this classic formula.