Arthur Conan Doyle weaves a dense web of mystery around the Baskerville family, whose lineage is supposedly cursed by a demonic hound of hell. The narrative begins when Dr. James Mortimer consults Sherlock Holmes following the sudden, mysterious death of Sir Charles Baskerville on the edge of the bleak Dartmoor estate. The autopsy reveals heart failure, but the distorted facial features and the gigantic footprints of a hound near the body suggest a terrifying reality behind the ancient family legend. Sir Henry Baskerville arrives in London as the sole heir, immediately facing anonymous warnings and the theft of his personal belongings, proving that a human enemy is actively orchestrating a campaign of fear.
Holmes dispatches Dr. Watson to Devonshire to guard the young baronet while he remains behind in London to untangle the financial and personal motives of the surrounding residents. Watson immerses himself in the desolate landscape, cataloging the local inhabitants, including the secretive naturalist Stapleton, his enigmatic sister, and the grieving butler Barrymore. The atmosphere grows increasingly oppressive as an escaped convict roams the desolate hills and an unidentifiable hound bays in the darkness of the Grimpen Mire, threatening anyone foolish enough to cross the moor at night.
Investigations reveal that the mysterious death of Sir Charles was tied to an unfulfilled late-night rendezvous with a local woman named Laura Lyons, who was manipulated by Stapleton. Holmes eventually arrives incognito on the moor, having deduced that Stapleton is actually a descendant of the Baskerville line who changed his name and plotted the elimination of his relatives to seize the vast family estate. Stapleton uses a massive crossbreed hound treated with a luminous chemical mixture to terrorize and physically exhaust his victims, making natural heart attacks appear to be the work of the supernatural.
The plot culminates in a desperate night chase amid a creeping white fog on the moor. Stapleton sets the monstrous hound upon Sir Henry, but Holmes and Watson intercept the beast, destroying it with their revolvers just in time. When they search Merripit House, they discover that Stapleton's abused wife has been locked away for exposing his murderous intentions. Stapleton flees into the treacherous depths of the Grimpen Mire, where he is ultimately swallowed by the quagmire. The narrative concludes with the restoration of order, leaving the surviving heir to recover from the ordeal through an extended voyage abroad.
