It is 1066 and in the aftermath of the Battle of Hastings the mutilated corpse of King Harold has been looted. The disappearance of a particular item enrages Duke William, and only one of his knights knows its whereabouts. In his remaining years this knight has to make a decision: will he ever share his secret, or take the greatest enigma in English history to the grave?
Centuries later, when Chester Bentley arrives at his new Devonshire boarding school, he is unprepared for the mystery it conceals. The discovery of an age-old riddle lures him and his new friends into a quest to uncover the secrets safeguarded by the stately manor house. Hidden somewhere in the county is an extraordinary treasure and the school holds the puzzling key to its surprising location.
But something is lurking in the dark, shadowing them each time they venture out from their dormitory at night, and a ghostly legend puts fear into the bravest of pupils. In their last year at the remote school time is running out; so can they succeed where others have failed, and even died, in a chilling hunt to reveal the last treasure of ancient England?