The Oversight (Oversight Trilogy) by Charlie Fletcher
Only five still guard the borders between the worlds.
Only five hold back what waits on the other side.
Once the Oversight, the secret society that polices the lines between the mundane and the magic, counted hundreds of brave souls among its members. Now their number can be tallied on a single hand.
When a drunkard brings a screaming girl to the Oversight’s London headquarters, it seems their hopes for a new recruit will be fulfilled – but the girl is a trap, her appearance a puzzle the five remaining guardians must solve or lose each other, and their society, for good.
As the borders between the natural and the supernatural begin to break down, brutal murders erupt across the city, the Oversight are torn viciously apart, and their enemies close in for the final blow.
This dark Dickensian fantasy spins a tale of witch-hunters, magicians, mirror-walkers and the unlikeliest of heroes drawn from the depths of British folklore. Meet the Oversight, and remember: when they fall, so do we all.