Ben Aaronovitch & Andrew Cartmel 
Rivers of London [PDF ebook] 
Night Witch collection

Press-ganged into helping a Russian oligarch hunt his missing daughter, PC Peter Grant and his boss, Thomas Nightingale, London’s only wizarding cops, find themselves caught up in a battle between Russian gunmen, a monstrous forest creature – and their nemesis: The Faceless Man. But as Grant and Nightingale close in on the missing girl, they discover that nothing about this case is what it seems! An all-new and original Rivers of London comic series, written by Ben Aaronovitch and Andrew Cartmel! Set between 'The Hanging Tree’ and 'The Furthest Station’.Collects Rivers of London: Night Witch #1-5