Dr Mortimer tells Sherlock Holmes about the curse of the Baskerville family, and how a vicious hound kills anyone from the family who resides there.
Dr Mortimer then mentions that on the plains by the house the body of Charles Baskerville was found with a giant paw print from a hound. However Sherlock explains that he has work to do in London and sends John Watson in his place
Then Watson meets Henry Baskerville who had gone to claim the house ,so he decided to stay with him whilst he was investigating . However at night Henry was woken up by the sound of a hound outside, but it turned out it was just one of the servants delivering food to his brother who was an escaped criminal and was now the first suspect...
Then Watson spots a dark figure outside who turns out to be Sherlock Holmes who had come to investigate a theory that the neighbour Mr Stapleton who owned a large hound had sent it after Mr Baskerville who had died of a heart attack at the sight of it.
However once Stapleton became aware that Sherlock was on to him he decided to try and kill Henry Baskerville, but Sherlock decided to use Henry as bait and wait for the hound to come after him so he could stop it.
Just as he expected, the hound came running at Henry and Sherlock shot it and caught Mr Stapleton who whilst trying to escape had fallen into a sinkhole on the plains.