Cal (short for Caledon) is the Queen's Assassin secretly in Renovia. His father had sworn a blood oath to the queen to find some magical scrolls, but then he died without completing the mission and passed it along to Cal. Cal desperately wants to find the scrolls so that he might live his life in peace. When he is searching for the scrolls, he saves a girl (Shadow) from a masked Aphrasian (a group who is trying to overthrow the queen), who turns out to be the former King's brother (the queen's brother-in-law). The queen decides to convict him and send him to a horrific prison, but she gives him a new mission. She will send someone to break him out of prison and travel to a neighboring kingdom to uncover a plot against her and take out the person who is behind it (even if it is the King there himself).
Shadow does not want to leave Cal in prison, and so, she creates her own plan to get him out. She tells him that she is to be his apprentice, as her own dream is to be a spy rather than a courtier. Together, they travel to Montrice.
What I loved: There is an interesting inclusion of history and some magic in the book. These all have a lot of promise and potential. I really loved the inclusion of LGBTQ people in several roles, such as Shadow's aunts, the male ambassador of Renovia who is married to a man, and a magical person who identifies as they/them, amongst others.
What left me wanting more: The pacing of the book is a little odd. The main focus seems to be trying to build a relationship between Cal and Shadow, but instead of building their communication, the book spends a lot of time on jealousy and physical desire. It was hard to cheer for them as it felt pretty forced. They are also posing as brother and sister, so there are many potentially awkward scenes in public that mostly seem to be overlooked. The big reveal at the end was pretty obvious from the beginning, and I was hoping for some more oomph. The pacing is very slow and then suddenly fast, mainly because the missions seemed to be a bit of a side note to the romance. I would have liked to get deeper into Cal and his motivations/personality as well as get more insight into their mission/operations. Thus, this book may be better suited for a younger audience (aside from mentions of sexual desire and a fade-to-curtains type scene, it's pretty clean and not much assassinations).
Final verdict: This is an interesting YA fantasy romance which may be better suited for younger YA readers. The kingdom and magic potential are really interesting, and I would be interested in seeing how the book develops in the sequel.