Catherine Fisher 
Conjuror’s Game [EPUB ebook] 

Alick is fascinated by Luke Ferris — the Conjuror! Where does he get his strange powers of healing? Why has he got six fingers? What is his connection with the sinister goings-on at the Mere in Halcombe Great Wood?Then Alick follows the Conjuror to the secret chamber under the hillside. There he discovers the ancient game of Fidchell and accidentally removes a key piece in the game — unleashing dark and terrifying forces on to the world.