Maybe 2.75 stars. I enjoyed the first 2/3 of the book a lot - very fun, darkly funny, interesting world, enjoyable characters. But the last third got a little bogged down in the thriller-y action scenes. Also, I found Yeats pretty annoying and his motivations were silly. I would've liked more of the book set in the school, as that's a favorite setting for me. Finally, this isn't usually a problem for me, but this book jumped around in time a bit too much with little warning, so some kind of chapter heading announcing the date or year would've been helpful. 
 Good for fans of Grossman's Magicians series.