CROUCHED on the grubby floor of an abandoned underground chamber, we attempt to contact the restless spirit of a dead child.
Just yards above our heads, traffic rumbles across South Bridge and the muffled cries of drunken revellers pierce the chilly night air.
But inside this forgotten cavern – one of many subterranean vaults dotted beneath this part of the Old Town – all is deathly still.
“I just felt something touch my arm,” insists Greig Pow, the founding member of the Lothian Paranormal Society, as torch lights swing round to illuminate him in the gloom.
The 41-year-old is part of a team of ghost hunters who are launching special, monthly tours of the Edinburgh Vaults, starting from this Hallowe’en.
The group hope to show people how a real paranormal investigation is conducted – by probing spooky goings-on within these secret, humid chambers just off the Royal Mile.
A catalogue of supernatural sightings have been logged in the underground rooms, formed under the arches of the South Bridge when it was first constructed in 1788.
Now largely closed to the public, they boast a history steeped in squalor and depravity, and were once home to some of Edinburgh’s poorest citizens.
Brave souls will be taken down into a discrete section of the vaults leased by City of Edinburgh Tours, who have teamed up with the paranormal investigators to find out once and for all what lurks in the dark beneath our feet.
And there’s plenty of hair-raising tales to investigate. In one cramped corner, a phantom woman known only as “Minging Annie” is often spotted crouched over, rubbing her arms and hair as the smell of burning fills the air.
In another, the voices of children have been heard in the dark. Creepy, worn-out dolls have since been placed inside to keep them company – and to terrify visitors.
It’s here that the Evening News, invited to spend the night with the group, watched as they attempted to reach out to the other side, an array of bizarre instruments on hand to help them make contact.
As well as an electromagnetic field (EMF) meter to measure any change in electrical current – which paranormal investigators believe could signal a spirit’s presence – they come equipped with a laser temperature gun and voice recorders, as well as handheld, CCTV and full-spectrum camera equipment.
Greig, who formed the Lothian Paranormal Society in 2012 with a couple of friends, insists investigations must be approached “with a sceptical mind”.
But he added: “There’s things we’ve captured that we just can’t explain. From my personal experiences, I find it hard not to believe that there is [something].”
Fellow investigator Joe Linden, 40, said: “We are trying to show that the paranormal can be explained. Understanding the paranormal is understanding the mind.”
On this particular night, the group are mostly relying on the EMF meter. As Greig asks questions, all eyes focus on the instrument to see if it will respond – hinting “something” could be trying to communicate.
“Who are you?” he calls out. “What’s your name? Were you tortured here? Were you happy here?” The silence seems to press in on us from all sides.
At one point, the flickering lights on the meter surge and recede as Greig walks around the cramped room – almost as if, he says, a spirit or other entity is creeping around us.
And as he kneels beside the dolls asking questions, he insists he feels something brush against his arm – a tickling sensation he can’t explain.
Later, some of the group hear the sound of heavy breathing in the gloom and their video camera is inexplicably turned off by an unseen hand.
But perhaps the most chilling event of the night happened before the News arrived.
As the team were staking out the area in preparation for the investigation ahead, a blood-curdling scream apparently issued from the corner where Minging Annie sits, rubbing her arms in the dark, trapped for all eternity.
“It was horrible,” said the group’s cameraman Mark Spiden. “It was one of the worst things I’ve genuinely ever heard.”
The verdict is clear. Something is going on beneath the bustling streets of modern Edinburgh – something that merits further investigation.
City of Edinburgh Tours and the Lothian Paranormal Society will be offering monthly ghost hunting tours from October 31.