Midnight Riot - Ben Aaronovich
Meet Peter Grant, Constable (Probationary) in London’s Metro Police Department. There are two things he wants out of life: to be a detective and to get in the uniform trousers of fellow Constable (Probationary) Leslie Mays. Unfortunately, it looks like neither will happen. The detective part has been stymied by his assignment to a desk job in the department of paper shuffling, while Leslie apparently intends to remain just chums.
That’s before he meets his first ghost… and becomes apprenticed to the head wizard in MPD’s equivalent of the X-Files. Inspector Nightingale is also the only wizard in “The Folly,” but fortunately he’s a jolly good one.
Peter’s laden with hidden talents: Nightingale knows because Peter can sense the vestigium; and that’s how you tell magic is afoot. And so begins his training; a remarkably Hogwartian affair with those Vulgar Latin words uttered while casting spells and the unpredictable results of beginner’s magic gone awry. In the meantime, Peter and Nightingale spend their time tracking down the evil… whatever... that is, for reasons unknown, wreaking havoc on Central London in the form of messy magical murders – very messy.

