Fatal Flaw - Tapa dura

At Thornton Hill Girls' School in Shropshire, England, most of the students have gone home for Christmas. All but Monica Shaw - and she is discovered dead in her room Christmas Day, an apparent suicide, and the dutiful Detective Chief Inspector Neil Paget is called to the scene. Though there are a few loose ends, there's little real evidence but the fact that Monica seems to have been an unhappy, unloved teen, and the case is closed.
Then a second death, a brutal murder-by-pitchfork at the school's adjoining stables, brings Paget to Thornton Hill again. The victim has a false name - and a snapshot of Dr. Andrea McMillan in his wallet. Paget, a widower in his late thirties who has been dating Andrea for the past few months, learns the hard way that nothing about this case is exactly what it seems. Though he can't believe it, his investigation is leading more and more toward the doctor. Then there's a third murder....