This book is something of a departure for the Roma Sub Rosa books, in that it makes no pretense to being a mystery. The question of whether Bethesda or the actress she resembles was kidnapped is settled very quickly (the fact that it was Bethesda is even revealed in the cover blurb), as is who was behind the kidnapping. The story instead is Gordianus's quest to locate the abductors and find a way to rescue her. Gordianus does a very small bit of detecting to unravel a conspiracy near the end of the book. The author's note claims Greek novels as a major inspiration for the story, and that is an appropriate comparison. It is an adventure tale, not quite as fantastic as the ancients might have made it, but certainly a bit larger than life at times.
I'll admit that I would like to get back to old Gordianus. The Roma Sub Rosa series began with a case that helped launch Cicero to prominence, so I've always thought that it needed to continue at least through Cicero's death. However, this was a rollicking good tale that made me happy that Saylor decided to spend a bit more time in Alexandria.