Around bleak Dartmoor, where the Hound of the Baskervilles once bayed, three children have been brutally murdered.  Now Richard Jury of Scotland Yard joins forces with a hot-tempered local constable named Brian Macalvie to track down the killer.The trail begins at a desolate pub, Help the Poor Struggler.  It leads straight to the estate of Lady Jessica, a ten-year-old orphaned heiress who lives with her mysterious uncle and an ever-changing series of governesses.  And as suspense spreads across the forbidding landscape, an old injustice retums to haunt Macalvie...with clues that link a murder in the distant pass with a killing yet to come.