Germany's Heligoland islands were part of the British empire in the 19th Century - but they were used to test British bombers after World War II and a vast explosion in 1947 caused massive destruction. Resentment still lingers, as Tom Blass discovered.
I was fighting off the cold with beer and bratwurst when my friend Judy suggested I speak to the boys in blue. Three men in uniform were nursing gluhwein in a corner of the makeshift bar that was really no more than a tent.
Crime is not one of the waves lapping at Heligoland's shores. The last murder - a crime of passion, apparently - took place more than 200 years ago. Few of the 1,600 inhabitants even bother to lock their doors.
But if not the Bronx, this small fog-bound candidate for the lost city of Atlantis still harbours secrets.
In fact, it turned out that my new drinking companions were not policemen after all, but a crack team of bomb disposal experts flown in from Schleswig-Holstein on the mainland.
"Busy day?" I asked.
In reply, I got a cold, but curious stare. Then one of the trio broke into a slow smile. "Two British bombs," he said. "Tomorrow we will send you the bill."
The other drinkers, Judy included, roared with good-natured laughter and there was another round of gluhweins, eiergrogs and schnapps. The joke, it seemed, had made everybody's day - and nudged away a degree or two of frost.
But it was more than just the usual Anglo-German banter.
For eight decades, Heligoland, seized during the Napoleonic Wars, was an unlikely outpost of British Empire in the North Sea.
But Germans still came. Tourists flocked here to swim and flirt while "dangerous" intellectuals pitched up to escape prison and the censor. A charming, bucolic touch was added by the islanders themselves, their quaint customs and their ancient dialect.
A Big Bang finished off the U-boat pens, in 1947
But in 1890, it all came to an end when the British government, as part of a colonial swap with Germany, traded Heligoland for the island of Zanzibar.
This delighted the German Kaiser, but outraged Queen Victoria who said "next we'd be giving up Gibraltar" and that she thought it was a "bad business".
So did the Heligolanders. Their idyll rapidly became a fortress and while the tourists still arrived on the steamer from Hamburg, the halcyon days were over. But grimmer changes were to come.
Erich Kruess, the island's archivist, was 13 when, on 18 April 1945, the Royal Air Force launched a sortie of 900 bombers. He remembers later emerging from a bunker into a cratered moonscape and being evacuated to Hamburg by ship. He, like all the other islanders, would not be able to return for another seven years.
He finds it hardest to understand what the British did in 1947. They decided to destroy the Germans' war-time U-boat pens and set off a huge explosion codenamed Big Bang.
This caused massive devastation. Buildings all around were destroyed, and a plume of smoke was sent spiralling high into the sky.
For another four years, the British used it as a testing ground for their bombers. It was even touted as a good place to test H-bombs until attention turned to the Bikini atoll.
Now only the newness of the houses and the broken bricks extruding through the turf give any hint of the scale of destruction.
His mild tone of voice belying any evident outrage, Erich says: "We were not even at war then. The British built Heligoland. Some of us had British passports and we never supported Hitler."
Much as he mourns for the buildings, he also grieves for the loss of a social fabric which had remained strong even in the years of exile. He fears the present generation cares little about the island's history. As a result, the islanders have become strangers to one another, he says.
But the young beg to differ. In fact, they complain about the way that everybody on the island knows everything about everyone.
Still standing: The big rock, Lang Anna
Even at Krebs nightclub it was clear that the youth contingent, however bleary-eyed, does feel engaged with the island's past.
At midnight, Judy's son Sven and I were getting on like a house on fire. Two hours later, it was our conversation that was getting heated. Between slugs of vodka, the 30-something Metallica fan began to vent his anger at what the British had done.
"They tried to destroy us. But look - Lang Anna is still standing!" notionally pointing towards the guano-clad pillar of rock which is to the island what the Eiffel Tower is to Paris.
Sven's friends gave a chorus of approval before reverting to a dance-floor the size of a dustbin lid. "Heligoland will always be German!" one shouted as a parting shot.
"What you have to understand about Heligoland
" said Sven. Then the diatribe juddered to a halt, overtaken by the vodka.
The island, I was learning, was a minefield in every sense of the word. "Is it hard work disposing of these bombs?" I asked the man from Schleswig-Holstein.
He sipped his gluhwein thoughtfully. "Yes," he said, "because they lie well hidden, close to the surface. Anything can set them off."
Or anyone, I thought. Anywhere. And I ordered another bratwurst to fend off the chill.
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