Evil has crept into the peaceful lives of the Daughters of Compassion. At first there are only small signs of its presence. The unnatural docility of Sister Joan's pupils at the little convent school on the moor. The disappearance of holy water, candles, and flowers from the convent chapel. The midnight flight of a beautiful au pair from the home of one of Sister Joan's students. With old Hagar the gypsy's warnings of malignant and imminent danger confirming her own deep alarm, Sister Joan begins gently to probe, seeking among her students and their families for the sources of the darkness that threatens this remote corner of Cornwall. And when a handsome adolescent boy inexplicably vanishes, she knows a killer is not far away. In a race with time and death, she pursues an evil as old as the human race.