After a brilliant debut (A Great Deliverance) and an almost as dazzling second novel (Payment in Blood), George's third mystery seems more modest--more an homage to the plot intricacies of Christie than a psychological twister in the manner of Rendell--but only for the book's first hundred pages; then the author swings into high gear as she un(Gordian) knots the old school tie. When housemaster John Corntel asks fellow Etonian Thomas Lynley, Scotland Yard CID, to find missing Bredgar Chambers' student Mattie Whately, Lynley somewhat offhandedly agrees, then becomes involved in earnest when the child's naked, tortured body is discovered in a cemetery by old friend Deborah St. James. Accompanied by tough-minded, working-class-reared Sgt. Barbara Havers, Lynley's investigation disgruntles the headmaster; antagonizes the school's principal benefactor, Giles Byrne (his son Brian is an unlikable house prefect); reveals housemaster Corntel's pathetic sexual fantasies; and almost comes to a dead halt when it collides with senior prefect Chas Quilter's loyalty to the school code of honor (resulting in his suicide). Finally, however, a tape recording implicates one student in sexual bullying, and another in blackmail that may have led to Mattie's death. Complications arise when the victim, like student suicide Edward Hus 17 years before, is revealed to have been half-Chinese and adopted. By the time Lynley and Havers sort through school politics, hazing rituals, sixth-form rites of passage, and the sexual mishaps of almost everyone--including the tormented Deborah--the solution is almost exquisite relief from the stress of living. Initially sluggish, in the manner dear to the cozy reader's heart, but George finally offers a piercing study of the education of a gentleman and his responsibilities and valor. Lynley, still lovelorn over Helen, seems emotionally opaque here, though Havers, in her family vise, fairly shimmers. Solid, fine-tuned writing--and a handsome companion piece to its two predecessors.