Another entry in the Rivers of London urban fantasy series (Whispers Under Ground, 2012, etc.).
In a city with a thriving supernatural community, including river gods, dryads and fairies, narrator and PC Peter Grant works for the London Metropolitan Police. He’s also an apprentice wizard and he, along with PC Lesley May and DCI Thomas Nightingale, the last registered wizard in England, comprises the Folly, the Met’s supernatural department—they’re known as Isaacs after their founder, Sir Isaac Newton. The case begins with a murder in Sussex that may have magical associations, followed by a suicide that may have been magically coerced. And when a valuable stolen book of magic is recovered, the thief turns up burned to a crisp—from the inside. The book, it seems, was owned by expatriate German architect Erik Stromberg, whose masterpiece, an eccentric tower block called the Skygarden Estate, in Elephant and Castle, clearly is magically inspired—but is the development itself some sort of magical artifact? Are these seemingly unassociated elements related to the Faceless Man, a powerful rogue wizard with whom the Folly has crossed swords in the past? To find out what’s really going on in Skygarden, Peter and Lesley must go undercover. All this is even more shapeless than the summary indicates—a phenomenon mystery fans will be familiar with—and it’s only in the last 50 pages or so that the plot coheres and the title’s significance becomes apparent. Still, you’ve got to like a book where the city itself is the main character—literally. And there are plenty of surprises for alert readers.
Worth a try for series fans, although, since Aaronovitch provides no catch-up help, newcomers are best advised to begin at the beginning.