This is exciting reading. We're in 15th century Europe at the end of the Byzantine era. All the rival city-states in Italy, Greece, and elsewhere are fielding networks of spies (some of them blackmailed), who move from place to place in disguise, trying to find out one another's designs on a moribund Constantinople, We follow the studly Eduardo Ferrucci, an orphan trying to make his way as a bookseller, as he is drawn into the Florentine network and begins his escapades. The background is Renaissance deluxe with lots of boastful merchants, dishonest servants, adulterous wives, and dramatic reversals of fortune.
A sociopathic and jealous spymaster working for the Bargello in Florentine security blackmails our hero into serving long years working for these baddies, who have their fingers on the pulse of Florentine society by way of access to the records of all the banks, plus the usual team of informants. Over in Constantinople there are lots of battles, skirmishes, swords flying, and blood spattering, while, back in Florence, the Security people exact their own kind of bloodless vengeance, bankrupting those they mistrust or see as obstacles to their own enrichment. When Eduardo isn't involve in battles, he is seeking out valuable books to send back to his bookseller boss. Some of the books he discovers trace back to ancient Greece, and were actual discoveries that influenced Renaissance thinking. There is a lot of bibliophilia throughout the book, as well as a lot of escapades of a more fleshly nature, as Eduardo can't seem to keep it in his tights.
I don't want to spoil the plot, so I won't tell you how the book ends, but it is fairly predictable.
The only problem I had with the work was with the omniscient narrator: using words like “life-style” and “rationalize” tends to spoil the suspension of disbelief in a novel set in the Renaissance. The author, a Renaissance scholar, also cannot refrain from using footnotes, further breaking the spell. Maybe some notes at the end, with suggestions for further reading, would be appropriate, but swashbuckling and footnotes don't mix. Also, the long sentences at the beginning of the book skate dangerously close to run-on territory. Raybould would do well to consult the masters of the long sentence, Yaacov Shabtai and Todd Hasak-Lowy.