Based on a novel by Arthur Conan Doyle, Sherlock Holmes with Watson solves a murder case in a mysterious place as another murder may occur.
In 1889 a man is running in the moors of Dartmoor in Devonshire, and the yowling of a hound is heard. He enters a gate and falls down. A haggard man finds him.
In the house at an inquest Barryman (John Carradine) says he found Sir Charles dead on the ground. The medical doctor James Mortimer (Lionel Atwill) says he died from heart failure because something was preying on his mind. John Stapleton (Morton Lowry) asks about his footprints. Frankland (Barlowe Borland) says he was murdered, but the coroner agrees with Mortimer.
At 221 Baker Street in London Sherlock Holmes (Basil Rathbone) tells Dr. Watson (Nigel Bruce) that Henry Baskerville may be murdered. His housekeeper brings in a walking stick, and Holmes sees it is Dr. Mortimer’s. He asks Watson what he can deduce from his stick. Holmes explains that he worked at the Charing Cross Hospital and has a dog. Dr. Mortimer knocks and comes in and confirms that his stick is from the hospital. He tells Holmes that his friend Henry Baskerville is in grave danger because every Baskerville has died mysteriously. He tells Holmes that he saw footprints of a gigantic hound nearby. He reads to them “The Legend of the Hound of the Baskerville.”
In 1650 the family is drinking around a table and laughing. Sir Hugo tells them about a woman and unlocks a door to show them. He says she is gone. He goes downstairs and orders his men out. His friends follow him. Hugo gets on a horse and rides off. They come upon the body of the girl and find she is dead. They hear the sound and then see a large hound. The friends see that Hugo is dead too.
Dr. Mortimer concludes reading the legend and asks Holmes to help him protect the young Baskerville. Holmes tells him to bring him to him, and Mortimer thanks him. Holmes asks him about his dog, but Mortimer says he only had a small spaniel that died. He leaves, and Watson asks Holmes about it. Holmes picks up his violin and starts to play.
A boat arrives at the dock, and Sir Henry Baskerville (Richard Greene) gets off. He tells ladies he has to go to the country. Dr. Mortimer greets him, and they shake hands. They get in a carriage to go to Northumberland Hotel. A rock comes through the window with a note which has words clipped from a paper.
Henry asks Holmes why one word is in ink. Holmes explains that the word “moor” is unusual. Henry tells Holmes that someone took one of his boots. Holmes says that Mortimer thinks he may not be safe on his new estate because of a ghostly hound. Henry is not worried and leaves with Mortimer. Holmes and Watson follow them.
Outside they walk on the sidewalk. Holmes tells Watson to watch a carriage. A gun is pointed from it, but the view of Henry is blocked. Holmes shouts, “Look out! Stop!” The carriage rushes off, and Holmes tells Watson to ask the police about the cab.
In an apartment Holmes, Henry, and Mortimer talk. Holmes tells Henry he was shadowed from his house. Henry finds his brown boot is back, but one of his black ones is gone. He says the brown ones are new. Watson comes in with John Clayton, the cabby. Holmes asks who his fare was. Clayton says he said he was a detective and was about 35. The name he gave was Sherlock Holmes. They laugh, and Holmes gives him money. He leaves. Henry says he is going to Dartmoor tomorrow. Holmes says he has pressing business, but he asks Watson to go with Henry. Holmes asks Watson to write him daily reports and goes out.
From the carriage Mortimer points out to Henry and Watson the giant stones of prehistoric man and the mire where many have died. They arrive at Baskerville hall and meet Barryman and his wife.
They go inside, and Barryman says not much has changed since Sir Hugo’s time. Barryman leads them upstairs and warns him about the step needing repair.
Watson writes a note to Holmes that the place is eerie. He sees the doorknob move and gets out a gun. Henry comes in quietly and says someone is prowling around. They find Barryman holding a candle by a window. Henry asks what he is doing. Barryman says he was checking the window. Henry tells him to get back to bed, and he goes. Henry looks out and sees a light. Watson signals with the candle, and the light outside goes out and reappears.
Watson leads Henry outside, and they walk toward the light. They find a torch in a rock. The haggard man runs off among the rocks, and Watson shoots at him. Henry says he would like to fire Barryman, but Watson suggests that they watch him instead. They walk back and hear a hound howling. Watson says he does not believe the legend either.
Watson is writing another note.
In the morning Henry sees Mrs. Barryman and goes out walking. Inside Barryman tells Watson about it, and he goes out. Barryman sees he is writing to Holmes.
Outside Watson is met by John Stapleton, who points out the dangerous moor where living things sink to their death. They hear a sound, and Stapleton says it is the hound. Beryl Stapleton (Wendy Barrie) on a horse shouts to Henry to warn him. He is glad to meet her. He asks about the hound legend. She says there are better places to live. Stapleton and Watson come up to them, and Stapleton is glad to meet Henry. Beryl invites Henry to dine with them. He thanks her for rescuing him.
Watson is writing more to Holmes.
At dinner Frankland accuses Stapleton of bodysnatching, but John explains that he studies the remains of primitive man. Mortimer says that he and his wife are interested in the supernatural and says she may consent to a séance; but she says not to tonight. They leave the table, and Stapleton shows them a skull. Mortimer comes in and says his wife consented. Frankland is a doubter, and Mortimer suggests he leave; but Frankland stays. They sit in a circle, and Mortimer has them put out the lights. Mortimer tells them to keep quiet. Mrs. Mortimer (Beryl Mercer) takes Henry’s hand and then speaks to Charles, asking him to speak to them. They hear the howling of a dog. Mrs. Mortimer asks Charles what happened that night. Beryl gets upset at the sound and stands up. Watson lights a lamp and asks Frankland what he thought it was. He says it was the hound of the Baskervilles. Beryl tells Henry she wishes he had not come there. Henry says she has been alone too much. He suggests they go riding in the morning, and she agrees.
Watson is writing to Holmes again and says that Henry is in love with Beryl already.
Beryl greets Henry and suggests where they can see the remains of ancient men. They explore them while walking. Henry tells Beryl that he likes her. When she is alone, she still fears the moor. He says he does not want to leave her, and he kisses her. Watson arrives and asks them to pause. Henry says they were getting engaged, and Watson congratulates them. They thank him. An old man with a beard is limping and tries to sell them a mouth organ or a whistle. Henry sends him off.
Watson gets a note to meet someone by the stone hut near the Grimpen mire. He asks Barryman who delivered the note, and he says he found it under the front door.
Mrs. Barryman hands some clothes to the haggard man. In front of the house Stapleton on a carriage asks Barryman if Henry is at home. Barryman says he is on the moor. Stapleton drives off, and from a room he uses a telescope and sees Watson walking.
Watson enters the stone cave carrying his gun. He lights a match and sees a note to sit down. The old man approaches, and Watson points his gun at him. The old man shows him an auto-harp. Watson warns him and asks who he is. The old man asks who he is, and Watson says he is Sherlock Holmes. The old man stands straight and pulls off his beard to reveal he is Holmes. Watson complains he made him write reports. Holmes says he has been free to work there. Watson denies he is in a huff. Holmes plays his violin. After they have eaten, Holmes says they should go back to Baskerville hall. Holmes says there is murder in his imagination. He tells Watson they must go beyond facts. They hear a hound.
A hound pushes a man off a high rock. Holmes leads Watson to the rock, and they see a body below. Watson thinks it is Henry, but Holmes finds it is a convict, a murderer who escaped and has been hiding there. Watson says he is wearing Henry’s clothes. Holmes says the hound was after Henry. He explains why the old boot was taken because it had the scent of the owner. Watson asks how he got Henry’s clothes. Stapleton comes up to them and introduces himself. He asks Holmes to shed some light on what has been happening there. They go back.
At Baskerville hall Holmes asks Barryman to get his wife. Henry is glad to see Holmes there. Mrs. Barryman comes in with her husband, and Holmes tells her that her brother is dead. She sits down and cries. Holmes says he fell off a cliff and informs Barryman he does not need to signal to him anymore. She asks Henry not to hold it against her husband. They go out. Holmes tells Henry that the man was demented and that his troubles are over now. Henry says he is going to Canada with Beryl, and they are being married in London first. Holmes says he cannot be at the wedding, but he invites them to dine with him in London before they sail. They look at the portrait of Hugo, and Holmes says it could be valuable.
On a train Watson asks Holmes questions. Holmes says the same man will try to murder Henry tonight. He says they are catching a train back, and he hopes to catch the man in the act. He is gambling with Henry’s life to save him.
At a dinner table Mortimer offers a toast to Henry and Beryl. Stapleton says he will be lonely again.
Holmes and Watson are in a carriage which breaks down. They are three miles away and go across the moors.
Mrs. Mortimer gives Beryl something old for her wedding. Frankland offers Henry a ride, but he declines. Mortimer warns him about crossing the moor alone. Stapleton says goodnight to Henry and goes inside. Henry says goodnight to Beryl and kisses her. He walks off.
Inside Stapleton tells Beryl it was a nice party. She says he and Henry will be back soon. They say goodnight, and she goes upstairs. John goes to his desk and puts on gloves and gets the black boot. He goes out.
Holmes and Watson are hurrying. Henry is walking slowly. John finds a crypt and opens it. A growling hound smells the boot and jumps out. Henry hears the hound. At home Beryl hears it too. Holmes says they will head him off. Beryl calls to Jack.
Henry looks around and keeps walking. The hound is after him. Henry begins running, and the hound growls. Holmes and Watson are running too. The hound attacks Henry who tries to fight it off. Holmes hears it and goes to the sound of the dog. He and Watson have guns and shoot. Watson gives Henry something to drink. Stapleton sees them. Holmes says he will be all right. Henry asks what it was. Watson helps Henry walk. Holmes with his flashlight follows footsteps. Stapleton is hiding and has a gun too. He follows Holmes to a cemetery. Holmes finds the black boot and the open crypt. Inside he sees bones and jumps in. Stapleton closes the top and locks it. He goes away. Holmes pulls out a knife and begins chopping at the door.
In the house Stapleton tells Henry and Watson he is glad they are all right. Stapleton says he saw Holmes on the moor, and he urges Watson to go to him. Watson leaves, and Stapleton attends to Henry, asking Mrs. Barryman for hot water. He gives Henry a glass to drink and says it may taste bitter. Holmes comes in and prevents Henry from drinking, breaking the glass. Stapleton says it was a tonic. Beryl comes in and comforts Henry. Holmes apologizes to Henry for jeopardizing his life. Beryl asks how he could know someone would attempt to murder him. Holmes says someone traced his lineage and trained the hound. He says the blame would have been put on the legendary monster. Holmes shows how the eyes of the painting are like those of John Sapleton, who pulls out his gun and runs out, knocking Watson down on the steps. Holmes blows his whistle and tells Watson that is their man. Holmes say he posted guards except on the mire. Holmes goes back inside and apologizes to Beryl. Henry thanks Holmes, and Mortimer agrees, praising Holmes for his work. Holmes thanks him and says he will turn in. As he leaves, he asks Watson for the needle.
This classic murder mystery borders on Doyle’s interest in the supernatural and spiritualism but does not actually explore them. The inimitable Holmes shows Watson how skillful he is at figuring things out, using his imagination as well as his extraordinary powers of perception.