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 ever-changing series of governesses. And as suspense spreads across the forbidding landscape, an old injustice returns to haunt Macalvie...with clues that link a murder in the distant past with a killing yet to come.