When thirteen-year-old Matthew Whately goes missing from Bredgar Chambers, a prestigious public school in the heart of West Sussex, aristocratic Inspector Thomas Lynley receives a call for help from the lad's housemaster, who also happens to be an old school chum.

Thus, the inspector, his partner, Detective Sergeant Barbara Havers, and forensic scientist Simon Allcourt-St. James find themselves once again outside their jurisdiction and deeply involved in the search for a child — and then, tragically, for a child killer.

Questioning prefects, teachers, and pupils closest to the dead boy, Lynley and Havers sense that something extraordinarily evil is going on behind Bredgar Chambers's cloistered walls. But as they begin to unlock the secrets of this closed society, the investigation into Matthew's death leads them perilously close to their own emotional wounds — and blinds them to the signs of another murder in the making...