Rivers of London: Rivers of London, Book 1

My name is Peter Grant, and until January, I was just probationary constable in that mighty army for justice known to all right-thinking people as the Metropolitan Police Service (and as the Filth to everybody else). My only concerns in life were how to avoid a transfer to the Case Progression Unit - we do paperwork so real coppers don't have to - and finding a way to climb into the panties of the outrageously perky WPC Leslie May. Then one night, in pursuance of a murder inquiry, I tried to take a witness statement from someone who was dead but disturbingly voluble, and that brought me to the attention of Inspector Nightingale, the last wizard in England.
Now I'm a Detective Constable and a trainee wizard, the first apprentice in 50 years, and my world has become somewhat more complicated: nests of vampires in Purley, negotiating a truce between the warring god and goddess of the Thames, and digging up graves in Covent Garden...and there's something festering at the heart of the city I love, a malicious, vengeful spirit that takes ordinary Londoners and twists them into grotesque mannequins to act out its drama of violence and despair.