The book continues the saga of Alex Verus, London-based mage and diviner extraordinaire, and his growing posse of friends/apprentices, Luna, Anne, Sonder and Variam, with some of the usual nemeses, and some new/old ones to be reckoned with.
Again, no interest in spoilers here, so what I will say instead is that this seems the grittiest of the four novels so far. Alex is forced into some harder choices than seen previously and confronts several demons/skeletons in his closet along the way. And some of the mental expectations you have of the story at the start take some definite twists and turns you may or may not expect. A great continuation of the series and VERY much looking forward to the next one!