Book excerpt: It is 1900, and Sarah Trevelyan, a pupil-teacher, is desperate to reclaim her family home, Darkwater Hall. Lost by her grandfather in a gambling wager, its present owner, John Azrael, is a mysterious man who draws her into a bizarre bargain ... the fulfilment of her dreams ... if she will only give up her soul. In 2000, Darkwater Hall is a private school for boys. Tom Hughes longs for the education found within its walls, but instead goes to the local school and has trouble with unpleasant bullies. His twin brother, Simon, who died at birth, is his constant companion, unseen or heard by anyone else. When Tom meets the strange girl Sarah, and a new teacher, Azrael, he finds himself embroiled in their deadly deal ...