Moon Over Soho by Ben Aaronovitch

This book finds PC Grant solving the mysterious deaths of jazz musicians during or just after gigs. It took a while for me to figure out where the plot was headed--the book didn't necessarily cohere as well as the first one, but in the end it was worth it. I particularly liked the way that the story added a big bad: an ethically challenged magician who went rogue sometime after World War II and is apparently training others in his nefarious ways. I'm looking forward to seeing where this series is going.