With a thunderous crash the window of Baskerville Hall breaks and a figure is flung into the moat beneath. The servant comes up gasping for air and with riotous laughter Sir Hugo commands that he be brought inside again and properly attended to. The quarrel involves the servant's beautiful daughter, whom Sir Hugo has kidnapped for his own pleasure. On going upstairs to fetch her with the intention of showing her off to his lustful friends, Sir Hugo discovers the window open and the girl gone across the moor. Infuriated with this humiliation, he sets the dogs loose upon her, despite the pleading of his companions. Mounting his horse, he follows the unfortunate girl across the moor. The dogs soon turn back, afraid of something that looms in the darkness.

Paying it no heed, Hugo wrestles the girl to the ground and kills her. He is then set upon by a gigantic hound from the darkness, who tears out his throat and is believed to stalk the Baskerville family for centuries to come. Sherlock Holmes (Peter Cushing) takes very little interest in the sordid tale brought to him by Dr. Mortimer (Frances De Wolff) until it is mentioned that one of the two final remaining Baskervilles has died in unexpected circumstances. Sir Charles was found in the very spot where Hugo met his misfortune, his face contorted in utter terror, dead of a massive heart attack. His successor Sir Henry (Christopher Lee) is set to come to England from abroad and reclaim the inheritance. Fearing for Sir Henry's life, Mortimer pleads with Holmes for intervention. Agreeing to take the case but sadly unable to leave London at least until the end of the week, Holmes sends Watson in his place to Dartmoor.

An expanse of barren wasteland and mires, the surrounding countryside is frequented with many strange characters and unusual noises. The Hall is situated not more than six miles from Dartmoor Prison, where one of the convicts has recently escaped. There are the Barrymores (John Le Mesurier, Helen Goss), servants who have kept the Hall for the Baskerville family for many generations. There's the good-natured, absent-minded local Bishop (Miles Malleson), who likes his sherry as much as scripture and collects deadly spiders. Then there is Stapleton (Ewen Solon), a local farmer whose daughter Cecile (Marla Landi) has a strange adversity to strangers. Watson has more than enough suspects and when you add ghostly howls on the moor, a figure in the darkness, a candle glowing from a shut up room in the Hall, and local quarrels, it unfolds in an intriguing take on the famous story by Sir Arthur Conan Doyle.

Initially I was surprised how much of the story had changed but by the conclusion, I wanted to applaud the scriptwriters for their unique perspective on a story that has been filmed numerous times. It's not wholly authentic to the book but the liberties taken don't appear to injure the plot, instead contributing to a bit more suspense on the part of the viewer, who isn't entirely certain that the villain will turn out to be who we expect. Most stories under-use Franklin, the nosy neighbor with a golden telescope. In this version he becomes the local clergy, which leads to some charming humor on his part, particularly when Holmes helps him fix his telescope. I was the most surprised by the alteration of Beryl's character from the book. Here she is a foreigner with a thick accent and riotous temper. The film takes a little getting used to but by the midway point you're hooked. Peter Cushing at first doesn't appear right for Holmes but he comes into the role with confidence. I think what I liked the most was the eccentric nature of Holmes that's brought out in his lodgings at Baker Street. Keen viewers with a good knowledge of the books will notice clever little nods to the canon, not the least of which being a bunch of papers "affixed to the mantelpiece with a jackknife."

There are less content concerns in this version than many others, primarily because for once it avoids the supernatural element of a séance that various adaptations include. There are several mild profanities and it's uncertain whether in the opening scene Hugo calls the peasant girl a "b*tch" or a "witch." He wrestles her to the ground and knifes her to death (unseen). Two people fall in a bog; one is pulled to safety and the other presumably drowns (we hear screams from a distance). A man is shot and turned on by a dog, who worries at his throat. Sir Henry is attacked by a giant dog, which is then killed. They find a body attacked by the hound, then discover later that it's been used in some terrible pagan rite (they describe it as being mutilated but viewers never see it). There is a mild sensual element involved. Cecile and Sir Henry kiss passionately after having known each other a few days and go to the ruins together. It's implied that Cecile believes he intended to take advantage of her there. She alludes to the fact that Sir Charles once attempted the same thing. Hugo's crimes against the peasant girl were of course in the nature of intended rape but the subject is never more than cleverly alluded to.

One of the best adaptations I've seen in the sense that it equally balances a smart sense of humor and equally engaging plot, this film did badly at the box office because Hammer produced it. Known for their murderous monsters and walking dead, audiences went in expecting a horror film and came out having seen a reasonably sane murder mystery. It's a pity the film was so misunderstood because it really is an enjoyable watch.