In a dramatic final scene, Holmes and Watson use the younger Baskerville as bait to catch Stapleton red-handed. After a late supper at the Stapletons', Sir Henry heads home across the moors, only to be waylaid by the enormous Stapleton pet. Despite a dense fog, Holmes and Watson are able to subdue the beast, and Stapleton, in his panicked flight from the scene, drowns in a marshland on the moors. Beryl Stapleton, who turns out to be Jack's harried wife and not his sister, is discovered tied up in his house, having refused to participate in his dastardly scheme.