The Dead of Winter — Chris Priestley

After Michael's parents die, he is invited to stay with his guardian in a desolate country house. He begins to suspect something is not quite right on the day he arrives when he spots a mysterious woman out in the frozen mists. But little can prepare him for the solitude of the house itself. His guardian is rarely seen, and there's a malevolent force lurking in an old hallway mirror. As the chilling suspense builds, Michael realizes that the house and its grounds harbor many more secrets-both dead and alive.