In the late winter dusk, hundreds of Vikings march down to the beach, bearing flaming torches. Their studded leather breastplates glint in the firelight as they roar and sing.
It is a scene that would have struck terror into the hearts of ancient Britons, and is also perhaps unsettling for modern politicians on both sides of Scotland's independence debate.
The fearsome-looking participants in a Viking fire festival known as Up Helly Aa live in Scotland's remote Shetland Islands, a wind-whipped archipelago where many claim descent from Scandinavia.
They aren't happy with the idea of Scotland leaving Britain to form an independent nation, and determined that their islands - closer to Norway than to Edinburgh - will retain their autonomy, whatever the outcome of September's referendum.
"Shetland is different. We have Viking blood in our veins," said the procession's magnificently bearded chief Viking, or Jarl - by day a housing officer named Keith Lobban.
There are only 23,000 Shetlanders, too few to make much difference to the outcome of the independence vote. But they have Viking-sized confidence, and a big bargaining chip in a chunk of Britain's oil and gas reserves which lie beneath Shetland waters.
Shetlanders are seeking new powers and official recognition of their special status - possibly along the lines of the Faroe Islands, a self-governing dependency of Denmark. The islanders feel their moment may have come, as Scotland's fluid constitutional status gives the chance to seek concessions from both sides of the independence battle.
Tavish Scott, Shetland's representative in the Scottish parliament, said an independent Scotland "doesn't have an economy if oil and gas doesn't happen. And that gives Shetland some leverage".
A 'yes' vote for independence on September 18 would trigger complex negotiations between Edinburgh and London over Scotland's share of Britain's offshore oil and gas - and of its trillion-pound national debt. A "no" vote is likely to lead to talks about giving Scotland more control over its economy and resources, and especially its energy reserves.
Authorities in Shetland, who have local-government powers such as collecting property taxes and running schools, see the referendum as a chance to drive a hard bargain, something at which they have considerable experience.
For centuries, Shetland was a poor place, ignored by governments far to the south and reliant on the unpredictable fishery industry and on making knitwear from sheep wool. But the islands have prospered since large reserves of oil were discovered in the 1960s.
Amid the rush of discovery, Shetland negotiated a generous compensation agreement with eager oil companies, creating an oil fund that has helped give the island chain well-paved roads, plentiful swimming pools and well-equipped community centres.
These days, oil production is dwindling, but French energy company Total is building a natural gas plant on the islands.
Shetlanders are keen to have control over their gas, fish and even wind - and are wary of government meddling, no matter where that government is based.
"Whether decisions are made in Edinburgh or in London, they are still distant from Shetland," said Adam Civico, editor of the Shetland Times newspaper.
An online petition on the Scottish government website calls for residents of Shetland, neighbouring Orkney and Scotland's Western Isles to hold separate referendums on whether to join an independent Scotland, stick with Britain or declare independence, although any of those moves would require protracted negotiations, and the petition has only 525 signatories so far.
A more likely scenario sees Shetland and Orkney demanding a bigger share of oil and gas revenue as a condition for joining Scotland.
For others, Shetland's strong sense of independence is balanced by a pragmatic streak that has led them to conclude their best bet is to remain in Britain.
"I don't think isolation works any more," said David Suckley, who runs an engineering firm in Lerwick. "We all depend on one other to such an extent nowadays. You can be too independent, and you're very lonely then."