Ghost Night book 4. Spoilers ahead for the earlier books, and earlier series.
The plan is to get to Artifel and get out as soon as possible. The first part works. . . .
It's a heavily magical city, and the First Magus lives there, and the Magisterium, having gotten word, wants Sophia to instruct. Politics are fraught enough to suggest a bargain: Caina can go and take Sophia if she tracks down the mystery of four deaths. Her aunt Ariadne is part of striking, and Caina has a chance to meet a very different aunt.
It includes permission to go somewhere, a forest that is protective, a house her aunt had built, a theatrical appeal to a man who's trying to assassinate her, a falling out between allies, magical mirrors, and more.