Rivers of London is the long-awaited original series from popular TV and tie-in writer Ben Aaronovitch. A darkly comedic police procedural, Rivers is a deliciously more-ish book that is nearly impossible to put down.
The book (and presumably, the forthcoming series) features Peter Grant, a somewhat crappy police officer who suddenly discovers that he's, well, magical. Or at least, suddenly aware of the magical. Young Grant was on the fast track to a bureaucratic desk job, but now his life is much, much more interesting. Grant is poached for duty by Chief Inspector Nightingale, the Met's divisional head (and the entire division) for Creepy Magical Stuff.
It all happens just in time. The Rivers of London, at least, their magical embodiments, are having a turf war - it is in the pushing and shoving phase, but still, if it goes wrong, the city will be in bad shape. Grant is also juggling a second supernatural case - a nasty serial-killer of a poltergeist is beating people to death and making their faces fall off.