This was such a delight of a story that I'm still thinking about it days later. The story is fascinating in and of itself--the main character is working tech support via phone, only for grimoires instead of traditional computer software, and the worldbuilding is absolutely exquisite, sucking us in immediately, and pulling us along a very tight-paced, wonderfully written high-stakes story arc. There's such a great atmosphere in this story, and it beautifully melds the parts of the story that may be familiar to the reader--whether it's tech support, call center work, or witchcraft--with the central conflict in the story, which ratchets the tension higher and higher until I was absolutely on the edge of my seat.
I highly recommend this story--and am eager to begin reading the next of Stuart's books.