Our writer gets into the Halloween spirit by scaring herself silly on a Hound of the Baskervilles tour, exploring the bleak landscapes that inspired Sir Arthur Conan Doyle’s novel

The wind is howling as I peer through the mist at a particularly bleak bit of Dartmoor, trying not to let my boots sink into the thick, black mud. I’m on the edge of swampy, fog-shrouded Fox Tor Mire, which was the inspiration for Grimpen Mire in Sir Arthur Conan Doyle’s book The Hound of the Baskervilles. It’s hardly surprising that this gloomy landscape inspired him to write one of his darkest Sherlock Holmes novels.

In the story, the detective is investigating the death of Sir Charles Baskerville, who died with a look of terror on his face, the footprints of a giant hound nearby. Conan Doyle wrote the novel after sharing a voyage from South Africa to England with Vanity Fair editor Bertram Fletcher Robinson, who regaled him with ghostly tales of his Dartmoor home.

Robinson helped him develop the plot, drawing on the legend of evil squire Richard Cabell. The author asked Robinson to scout possible locations, which Robinson did with the help of a Devonshire neighbour, the Reverend Robert Duins Cooke.

Facebook Twitter Pinterest A foggy morning on Dartmoor. Photograph: David Clapp/Getty Images

Now, 85 years after Conan Doyle’s death, Cooke’s great-grandson, Alex Graeme, has become a Dartmoor tour guide too, and on this gloomy autumn day, his spooky eight-hour Hound of the Baskervilles tour seems the ideal way to get in the mood for Halloween.

“My great-grandfather absolutely loved Dartmoor,” says Alex. “Back in those days the roads were awful and getting around the moor was difficult, so the fact that he dedicated so much time to getting to know it shows his passion for the place.”

Getting around the moor is significantly easier these days. At £360 for groups of up to six, Alex’s tour is on the pricey side but he has spent years investigating Dartmoor’s myths and legends and aims to help visitors understand why this place and its people inspired Conan Doyle.

Facebook Twitter Pinterest The spectral hound left material footmarks according to Dr Watson

In the pretty village of Ipplepen, Alex shows us Park Hill House, Robinson’s former home, and the much smaller 2 Wesley Terrace, home of Henry Baskerville, who was Conan Doyle’s chauffeur during his visits. A mile out of the village is the 13th-century Old Church House Inn – considered one of the UK’s most haunted – where Conan Doyle and friends went drinking.

Back in Ipplepen, St Andrew’s church has beautiful stained-glass windows and, in the churchyard, the crooked gravestones of Robinson and Reverend Cooke.

A few miles west, on the edge of the moor, Buckfastleigh’s Holy Trinity church is a fragile skeleton, after a fire in 1992. It’s the resting place of the dastardly 17th-century squire Cabell, thought to be the inspiration for the character of Jack Stapleton, who hides his vicious dog on the moor.

“The squire was a violent brute,” says Alex. “When he died, locals were petrified that his spirit would escape, so they buried him in a coffin sealed with a thick slate lid, and enclosed it in a special tomb.”

Standing in the shadow of its overhanging roof, I give an involuntary shiver: the iron bars and reinforced stone coffin seem out of place in this peaceful place. Though on stormy nights, the squire’s hounds are said to howl outside his grave, and it is said that if you run around his tomb seven times then poke your fingers through the bars, they’ll be nibbled by Cabell.

Facebook Twitter Pinterest Squire Cabell’s tomb in Buckfastleigh

Leaving Buckfastleigh, we drive up on to Dartmoor in a biting wind. It’s a spooky place, with swirling mist, and roads that disappear into bracken. And in one of its remotest corners is the notorious Fox Tor Mire. “A false step yonder means death,” evil Stapleton warns in the book. Alex explains that a vast granite bowl beneath our feet prevents water draining away, creating the swamp into which Stapleton eventually disappears.

In the novel, Dr Watson talks of “a spectral hound which leaves material footmarks”, and Holmes suspects that Stapleton used phosphorous to give the hound its eerie glow. As we drive along Dartmoor’s foggy lanes, Alex tells me that today’s visitors often stumble across similarly fluorescent beasts – but these are less scary glow-in-the-dark ponies, painted with reflective paint to make them more visible to drivers.

Facebook Twitter Pinterest Mist envelops the church tower of Widecombe-in-the-Moor Photograph: JAI/Corbis

We round a corner and are faced with the huge stone hulk of Dartmoor prison, near Princetown. It’s impossibly bleak – a fortress surrounded by vast moorland. In The Hound of the Baskervilles, locals live in fear of Selden, an escaped murderer who roams Dartmoor. Over a fireside pint at the cosy Rugglestone Inn, in Widecombe-in-the-Moor, Alex tells me of plans to close the prison and turn it into a whisky distillery.

I tell him we’re staying at beautiful Orestone Manor. “You know about its history?” Alex says. Fearing stories of haunted hounds and curses, I’m not sure I want to hear it. But Alex tells me its former owner was John Callcott Horsley, creator of the world’s first Christmas card. My husband swears he sees a mysterious shadow in our room that night, but I like to think it was just Horsley, reminding me to make a start on my Christmas card list.

• The tour was provided by Alex Graeme of Unique Devon Tours (uniquedevontours.com). The Hound of the Baskervilles tour costs £360 for up to six, including transport and entry fees. Accommodation was provided by Orestone Manor (doubles from £110B&B, 01803 897 511, orestonemanor.com) , which can help put together a group for anyone interested in the tour