This book, published in 1902, is about a ghostly mad-dog that has haunted a family for hundreds of years. When Sherlock Holmes looks into the mysterious death of Sir Charles Baskerville, strange events begin to take place in the creepy countryside.
Dr. Mortimer is so sure that the Hound is responsible for Sir Charles' death that he doesn't think it's worthwhile for Holmes to investigate further. he doesn't want to make Sir Henry another victim of the Hound's appetite for Baskervilles.
But there is something weird going On at Baskerville Hall, and it seems to center on poor Sir Henry, the new heir. So when Sir Henry makes plans to return to his old family home, Holmes asks Watson to go with him as a kind of bodyguard/investigator combo.
Meeting Sir Henry' neighbors he comes upon Mr. Stapleton and learns some information helpful to the case. Mrs. Stapleton approaches Watson with some alarming news pertaining to the recent arrival of Sir Henry.
Holmes tells Watson that Stapleton the killer. But while Holmes is sure that Stapleton is the murderer of Sir Charles Baskerville, he has no proof that would stand up in court.
Holmes set up his final ambush of Stapleton. Stapleton bullied Laura into keeping quiet about the meeting after Sir Charles' mysterious death. Once Holmes sets up Sir Henry as bait by sending him off to dinner with Stapleton that night, they're ready to catch Stapleton red-handed in an attack on Sir Henry.