Thirty or so people move slowly across a muddy field in the pouring rain - and they think it's fun.
They've each got a metal detector, a small spade and - the most optimistic among them - a bag for treasure.
They don't like to be labelled treasure hunters though. They prefer to call their hobby - quietly searching these bleak, rain-soaked slopes - metal detecting.
There has been a recent rise in interest in the pastime - since David Booth unearthed a hoard of Iron Age gold the first time he used his new metal detector.
He found the four neck ornaments - or torcs - dated from between the 1st and 3rd Century BC in a field near Stirling in September 2009.
Mr Booth is, like the others, intently listening to the electronic beeps from his metal detector against the constant background roar of traffic on the nearby M80.
Ian Brown, from Galashiels, is a moderator on Detecting Scotland, the web forum which brings these metal detector enthusiasts to these rain sodden fields.
His avatar on the forum is "Reiver" and his signature reads: "One day it'll be GOLD!!!"
"There should have been more of us today," he says. "The last meet had 60 members but this was a bit short notice."
"Davie's finds have been a great help all round. A lot more farmers are keen to let people detect now and the forum has really brought people together."
For this dig, a farmer has given permission to search five fields adjoining the A872 north of Denny.
There is big excitement at the discovery of three coins: two Elizabethan sixpences from the 1560s and a shilling from the reign of Charles I.
"Any find over 300 years old has to be reported to Treasure Trove. Normally if they aren't extremely rare they are returned after a few weeks," Mr Brown says.
Who knows how long it is since these coins fell out of someone's pocket, or an unfortunate horseman lost his purse.
Now, they are brought back to view by some lucky combination of 21st Century technology and the turn of the tractor's plough.
Another member of the group, Brian Kenny from nearby Cambusbarron, says: "Every metal detector enthusiast dreams of finding a hoard of coins and I suppose you could say we are a bit of a bunch of anoraks.
"But I do it, like I think most of the others do, because first and foremost I am fascinated by history."