The story begins with Sherlock Holmes and Dr.
Watson; in their office in London.
They examine a cane left in the office by an unidentified visitor.
The arrival of Mortimer who presents them with a document, dated 1742, that reveals the legend of the Baskerville curse.
Hugo Baskerville was fixated with a local girl, whom he kidnaps.
The girl escaped and Hugo makes a deal with the devil and sends out his hounds to search.
His friends come upon the bodies of both.
Ever since, a beast has haunted the Baskerville family.
It had just killed Charles Baskerville.
Mortimer came to ask what to do about Henry, mentioning Charles's brother Roger, who is thought to be dead.
Henry had received a warning by an anonymous note.
Then Henry claims his boot was stolen.
Holmes suspects someone is following him, and he is right.
Henry's decision to go to Devonshire cause Holmes to sends Watson as well.
The group is met by police, looking for an escaped con.
Watson hears a woman's crying that night.
They ask Barrymore about it.
Watson finds he is lying.
He learns that the telegram was delivered to Mrs.
Barrymore, and her husband claimed to be upstairs.
Mr.
Stapleton comes up, calling Watson by his name.
Stapleton points out the danger of the place, mentioning the mire.
Watson then meets with Miss Stapleton.
Believing he is Henry and tells him to go back to London and say nothing to her brother.
Later after learning that he is Watson, she tells him to forget her warning and she tries to convince him that she was being concerned about the curse.
Watson reports about the escaped con, which no one has seen in two weeks and about the relationship between Henry and Miss Stapleton, and that Mr.
Stapleton seems unhappy about it.
He mentions meeting Mr.
Frankland of Lafter Hall.
Watson tells how Barrymore confesses that he did not receive the wire himself.
He is woken by footsteps outside his door and someone sneaking down the hall.
Watson suspects that he is having an affair, which would explain his wife's crying.
Henry's romance with Miss Stapleton brings about her bother yelling and acting strangely.
Later Mr.
Stapleton apologizes for his behavior.
Watson and Henry confront the butler.
Mrs.
Barrymore arrives and explains everything.
The escaped con is her brother, and they have been feeding him.
Henry and Watson go to capture the man.
On their way, they hear the loud moaning of a wolf.
They find where the con is hidden.
The man escape's, but Watson catches sight of a different figure, but as it is quickly gone.
They agree not to tell the police, and Barrymore thanks them by giving another clue about Sir Charles.
That he went to the gate on the night he died to meet a woman, and tells of a letter, signed L.
L.
Watson learns that Laura Lyons, daughter of Frankland, who was married against her father wishes and that both her husband and father deserted her.
The shadow, Selden has seen and tells that the man lives in a hut and is getting his food from a boy.
Laura admits that she wrote to him and that it was Stapleton who told him about her.
He asks what happened that night, but she claims to have missed the date and refuses to tell why and adds that she has gotten help from someone else.
Watson searches for the stranger and finds the hut, and there waits for his return, it is Holmes.
He then explains why he lied to Watson.
He reveals that Laura and Mr.
Stapleton had an affair and that his sister is really his wife.
Holmes tells of his search into Stapleton's past.
They hear a scream in the moor.
When Stapleton sees that the body is not Henry and acts strangely.
A portrait reveals a comparison between Hugo and Stapleton, giving a clear motive.
Holmes tells Henry that they are going to London, and tells Henry to trust him.
They go to tell Laura about Stapleton's marriage.
She reveals that he had offered to marry her if she got a divorce, but would need Charles help.
He wrote Laura's letter to Charles and then insisted she not go.
The detectives hide and a thick fog settles.
They hear the hound and shoot it but dose not die, then it leaps at Henry but Holmes fires more and the hound falls.
They find it is covered with phosphorous to make it glow.
They knew the glow of the hound was what scared Sir Charles to death.
Finding Mrs.
Stapleton bound and gagged, she tells them about her husband's hiding place and she leads them through the mire.
They find on an almost submerged black boot which was Sir Henry's.
Stapleton footprints are now gone and they decide that the mire has killed him.
Back in London Henry and Mortimer visits them to get the full details of the case.
Stapleton was actually the son of Roger Baskerville, and that he went to Devonshire to plot his chance at the Baskerville inheritance.
Stapleton took his wife with him to London, where he followed Henry and she tried to warn him.
He stole one of Henry's shoes to give his hound the scent.
Holmes then states that the letter smelled of perfume, and that the idea of a woman made him think of the Stapleton's and how he used Henry to catch Stapleton.
Mrs.
Stapleton warned Henry but did not reveal her husband.
When Henry came to dinner, she realized he had his hound in the outhouse, and she confronted him.
He told her of his relationship with Laura, she reacted, and he tied and gagged her.
The only thing not explained is how Stapleton intended to claim the fortune.
Holmes has a guess, but he admits that he cannot foresee into the future.