Back Bay Books, 2016
Stiletto is the sequel to The Rook. These books are sometimes referred to as The Checquy Files, although as far as I can find there is no third book currently in the works. This is a pity, because if anything, Stiletto is even better than the first book.
You could probably read and enjoy Stiletto without reading The Rook. However, you shouldn't. The second book contains a number of spoilers for the first (as will this review). However, if you have read (and enjoyed) the first book, you should definitely read this one as well.
Spoilers! The story picks up not too far after the end of The Rook, but moves away from Rook Thomas a bit, to refocus on some new characters: Pawn Clements, an up-and coming Checquy footsoldier; and Odette Leliefeld, part of the Grafter delegation to England. The Grafters are petitioning the Checquy for a peaceful alliance -- something that neither side wants -- but this being a secret paramilitary organization patrolling the supernatural, there are some distractions that keep the negotiations from going as smoothly as they might. Moreover, it emerges that some of these distractions are not domestic, but a continental group that is hunting down and killing members of the Graffers. Given the organization's contentious histories, the groups are split on how much they can trust each other, although it quickly becomes apparent that they may not have a choice. End Spoilers.
Overall, a good story, and in some ways better written than the first book in the series. While The Rook was very much focused on the new, exciting, and often violent events in supernatural England, Stiletto focuses a bit more on the characters, and uses the weirdness, adventure, and violence a bit more strategically, to punctuate the storyline, rather than overwhelm it. I highly recommend it, but, as I mentioned, you should really read the first book first for maximum enjoyment.