Dartmoor, with its mists, bleak winter weather and overwhelming sense of isolation, is the perfect place to build a prison. It's not a place many would choose to live - yet the Governor of Dartmoor Prison did just that. When Herbert Russell retired, he bought All Hallow's Hall - a rambling Tudor mansion on the edge of the moor, and lived there all his life.

Now he's dead, and his estranged family are set to inherit his estate. But when the dead man's family come to stay, the atmosphere of the moors seems to drift into every room. Floorboards creak, secret passageways echo, and wind whistles in the house's famous priest hole. And then, on the morning the family decide to leave All Hallow's Hall once and for all, their young son Timmy goes missing.