The Devil of Winterborne has only recently been exorcised by P.R.O.B.E. But when the body of its last victim disappears, and a book of black magic spells is stolen from a local museum, Liz Shaw begins to wonder if the ghosts of the past have really been laid to rest. Forced into an unholy alliance with the school's disgraced headmaster, Liz must fight not only her own warring emotions, but a festering evil that threatens to corrupt the Earth again after 100 years. But how do you fight a shadow from hell?