I'm giving this a 4 instead of a 3 because of the last 50 pages and especially for this:

"He remembered something Belisha had told him that day in Kestrel Courtyard after the miraculous door appeared. He had asked her if the place had become so evil and corrupt because of the manticore, and she said - in typical night crow fashion - yes and no. She said that sometimes people have a strange habit of inviting hate into their house when they don't get what they want or when someone hurts them. 'Don't ever let that happen to you, Foxling,' she said. He hugged her neck and assured her he wouldn't."

Overall, I give the book a 3.5 or 3.75 stars.