I have to start out mentioning that I was debating between 4 and 5 stars (5's almost never happen, unless your Sarah J. Maas), that's how good it is. I have a feeling the next one will be a 5 so we can stick with 4. I completely recommend this book and REALLY want the next!
When Laia's brother, her last family member alive, is framed for treason she will do anything to get him back. Trading safety for shackles, Laia is tasked with spying in the Martial Empire's best military academy. Just looking at these beasts wrong will get you earn you a painful death, but when they find out who she really is... Her greatest ally inside the walls is Elias, the star student of the school. They both have a common goal, freedom. Will it be Laia or the Empire that burns?