This is extremely fast paced and very much focuses on the murder mystery side of the book. If you like reading about true crime and wish to combine that with fantasy, I think this is the book for you. 

I would say this book is very plot forward. The world building isn't immediate, but it is medieval inspired so there is not much to learn other than the religion and magic system. I personally enjoy plot heavy books where the story is following events rather than the characters. 

We are reading from the POV of Cat, who is an orphan who works for an architect designing the Holy Sanctum (which in my mind translated to massive Catholic cathedrals). She is able to spot flaws in the construction and climb on the scaffolds easier than others. I found this setting very interesting and unique, as it's something I've never read much about before. Cat becomes involved in the investigation after becoming a witness to the first murder, where she gets closer to Simon, the detective, who is cousin to the children of the Executor of Justice. As Cat gets further drawn into the investigation, we learn more about Simon and his cousins, Juliane, Lambert, and Oudin. 

The romance is slowburn and enjoyable in this book, but it is not the main plot. I did find the predict the killer about halfway through the book, but regardless I found it interesting. This book combines fantasy and murder mystery so well and in such a unique way! Overall, I immensely enjoyed it. It did wrap up the story well so I am curious what the next book will follow as I heard it would be a duology.