Since his recent death, Latona has been able to relax a bit, as have many who were exiled from Aven during Ocella's reign, including the handsome Sempronius Tarren, a Popularist Senator who has returned to Aven hoping to bring about massive change. Sempronius is also a mage, of Shadow and Water, but as a politician, he is forbidden to use magic. Sempronius finds himself drawn to Latona, despite the fact that she is married to a boring merchant named Herennius.
As Latona and Sempronius find themselves thrust together again and again at social and political gatherings, especially since her father and Sempronius are political allies, the pair begin to have feelings for one another, but also realize that they both share lofty goals and possibilities for themselves and the city of Aven. As Sempronius and his plans for the city gain traction among the citizens of Aven, especially those of lower class who aren't typically courted by politicians, Lucretius Rabirus becomes a dangerous enemy to Sempronius. Rabirus was the right hand of Ocella and often carried out his wicked plans, and with Sempronius possibly getting in his way as he seeks higher office, Rabirus has no problems playing dirty, and by that I mean using dark magic to stop him.
Meanwhile in neighboring Iberia, Latona's brother, Gaius Vitellius, is stationed with the military there and bears witness to a new and dangerous threat to Aven and its allies in the region. A Lusetani war chieftain named Ekialde is using blood magic, with the help of his uncle, a magic-man, and is gaining many followers as he rampages the countryside, burning villages and murdering their inhabitants. Aven's allies fear that they will fall prey to the "erregerra," as he is called, and look to Aven for protection. Fortunately, Sempronius is gung ho to start a war in Iberia and rid the land of this nuisance once and for all, but not everyone feels the same way.
From Unseen Fire is an interesting book, but it's a bit of a heavy read. It is very clear that Cass Morris has a serious world to build here and this first book is spent establishing the characters and the world of Aven and its surrounding communities. There's not a whole lot that happens, aside from a thrilling assassination attempt, some arson, and okay, well there is a dark magic showdown, but I felt like slowly building this world was necessary. I will warn you that if you don't have much of a grasp of Latin, you may find yourself looking at the glossary often. I took Latin in college and have a fondness for the language, but Morris uses a great many Latin words in simply describing the homes and inhabitants of Aven, so be prepared. I found it to be incredibly immersive because of this, but your mileage may vary.
There are also a great many characters introduced, and Morris uses the names properly, so again, if you aren't familiar with Latin, you may wonder why Latona Vitellia and her father, Aulus Vitellius have a similar but not exact last name. It's a Latin thing.
I really enjoyed reading about Latona, Sempronius, and the citizens of Aven, but not so much the Lusetani and Ekialde, but since he is a villain of sorts, that's probably intended. I typically read books very quickly, but this one took me longer than most, probably because it was so meaty and also peppered heavily with the Latin language. If you are a fan of Latin and old Rome, you'll probably really enjoy From Unseen Fire. Much was set up in this book for not only Latona and Sempronius, but also Latona's sisters, Aula and Alhena, and her brother, Gaius. As Latona's powers increased throughout the book, I became more drawn in and I'd love to see where this series goes. It's a slow burn, but I feel confident that this series is going to go to some very interesting places.