Sherlock Holmes and Dr. Watson are approached by Dr. Mortimer to investigate the mysterious death of Sir Charles Baskerville on the wild, eerie moors of Devonshire. The legend of a supernatural hound that has plagued the Baskerville family for generations is revived with this recent death, fueling local superstitions. Holmes, suspecting foul play rather than a spectral beast, sends Watson ahead with Dr. Mortimer to protect Sir Henry Baskerville, the new heir arriving from Canada. Sir Henry receives a series of ominous warnings to stay away from Baskerville Hall, heightening his apprehension and setting Watson and Mortimer on edge.

As Watson delves deeper into the mystery, he encounters various suspicious characters, including the reclusive naturalist Stapleton and his enigmatic sister, Beryl. Strange occurrences and eerie howls in the night further unnerve Watson and Sir Henry. Holmes eventually joins them, having secretly been observing their progress. Together, they close in on uncovering the true nature of the threat that has cast a shadow over the Baskerville line for centuries. The investigation reveals a web of intrigue and deceit far more tangible than any ghostly hound, suggesting that human treachery could be more terrifying than any myth.