There’s something about the mid-century teak wood panelling covering much of the interior of Grangemouth Sports Complex - and indeed the retro scoreboard on the wall - that makes me think of East Germany in the 1970s. Not that this is a bad thing in my book; as a Brutalism aficionado I’m always keen to see interesting examples of the style.

The centre is hosting the Scottish declaration for the European Union referendum and I’m embedded overnight alongside an army of fellow journalists, keen to soak up every twist and turn. The caffeine is flowing freely and I joke with colleagues early on in the evening that the East German connection is a surely a sign that the UK will vote to Remain in the European Union. We all laugh. The final polls point to a very close contest, but most have a small margin for Remain. Soon after, another fixture of the hall, a pair of swing doors behind a BBC presenter, provides further German-based comedy value; at one point #HitlerDoor is trending on Twitter across the UK.

Just a couple of hours later, however, no one is cracking jokes any more. In fact, it’s unusually quiet for a count. We’re all silently glued to televisions and social media because the latest results from England and Wales appear to be signalling a narrative that, if we’re honest, nobody really expected: Brexit is happening before our eyes.

At first the early Leave votes in places like Sunderland could seemingly be explained away. “And wait till London comes through,” everyone had nodded to one another knowingly, as one Scottish local authority after the other voted emphatically to Remain.

Sitting on a bench at the side, the SNP Central Scotland contingent – MP Martyn Day, MSP Angus MacDonald and councillor Paul Gardner - look relieved as the Scottish results emerge; more SNP voters than they expected had signalled they might vote out, they told me. But as the Leave vote takes a notable lead, Remain faces start looking decidedly glum.

The big change in atmosphere comes around 4am, when the ubiquitous Professor John Curtice of Strathclyde University, the poll expert’s poll expert and interpreter of public opinion extraordinaire, declares on the BBC that Leave is now favourite to win. ITV and one of the big betting companies are saying the same. The pound has just slumped to its lowest level against the dollar in more than 30 years.

At the beginning of the night, it felt like the representatives of the Scottish Leave campaign were here to make up the numbers. Now their excitement is palpable; they may have lost the Scottish battle, but the war, it seems, has been won.

At this same 4am juncture, Scotland’s Cabinet Secretary for External Relations, Fiona Hyslop, a Remainer, looks grave. Over recent days I’d spoken to a number of people who suspected many in the SNP, even at Cabinet level, were secretly hoping for a Brexit. If this is the case, Ms Hyslop is hiding her glee well. She appears genuinely shocked by the direction of travel in England and immediately talks of “ensuring Scotland’s interests are protected” and “exploring all options”.

The SNP hierarchy is clearly still working on its response; Ms Hyslop doesn’t say outright at this point that there will now have to be a second independence referendum – First Minister Nicola Sturgeon confirms that Indyref 2 is “on the table” later in the day – but there is a distinct edge of anger to her voice as Prime Minister David Cameron is mentioned.

“Look, if I’d believed Cameron that the way for Scots ensure membership of the European Union was to vote No in 2014, I’d be feeling pretty upset right now.

“I don’t doubt that many No voters will now want to think again about their decision. I believe there will be a considerable reappraisal.”

As for where all this leaves the UK, she is scathing. “To say the UK has many bridges to build is an understatement,” says Ms Hyslop. “It will have to reassess its place in the world.”

We move on to the tenor of the Leave campaign that has persuaded the people in England and Wales to take such a momentous step. Has it been xenophobic, I ask? She stops short of saying it has, but contrasts the events of September 2014.

“What I will say is that the Leave campaign has been all about what you are not. This was not the civic nationalism we saw during the independence referendum. Forces were unleashed that are turning Great Britain into Little England.”

Back in the Leave camp, tired faces are struggling to take in the historic nature of the victory this disparate group of Labour, Tory and Ukip have engineered. Former Labour MP Tom Harris, who led the campaign in Scotland, seems as shocked as Ms Hyslop at what is unfolding.

Back in the hall, the all-Scotland declaration is made at dawn. Scotland has, as expected, voted to Remain. But events elsewhere in the UK have overtaken this moment and it now seems imbued with a hollow, rather meaningless edge. It will be weeks and months before Scotland comes to terms with its wider significance.