Profile: Can SNP defend two-vote majority in North East Fife?
It was the tighest marginal seat in the whole UK in 2017, won by the SNP's Stephen Gethins.
After three recounts, and on a margin so thin it amounted to 0.004% of the vote, the SNP held on in North East Fife by the skin of two teeth back in 2017.
Two years ago, a pair of votes separated the nationalists' Stephen Gethins and then-Liberal Democrat candidate Elizabeth Riches.
Perhaps losing by such fine margins scarred Ms Riches, because this time round, Wendy Chamberlain is contesting the constituency for the Lib Dems.
A former police officer, Chamberlain has previously stood for the party in council elections and as its Westminster candidate for Stirling two years ago.
She told STV News: "We're very confident. We held this seat from 1987 to 2015... and we've had Willie Rennie here as the constituency MSP since 2016.
"So this is definitely a seat with a Liberal tradition and having come so close in 2017, absolutely, it's our top target seat."
She concedes that the party still gets some negative feedback on the doorstep about its time in coalition government with the Conservatives from 2010 to 2015.
The Lib Dem candidate said: "I do genuinely believe that we went into coalition in 2010 with an intention to do the right thing as a response to the economic crisis.
"I do get it occasionally on the doorsteps - tuition fees very occasionally as well - but in the main we're in a completely different scenario now post-EU referendum."
Chamberlain believes Brexit, and local opposition to it, is the defining issue here and says the Liberal Democrats offer the "clearest, most positive Remain option" for voters.
"It's quite clear in the last three and a half years from people I have spoken to, and working with Willie Rennie, that there are a number of economies within North East Fife, tourism for example, University of St Andrews as our major employer, agriculture and our fisheries, that are going to be negatively impacted by Brexit," she said.
"There's no evidence to me that the position of this constituency has changed - it's a Remain constituency."
But in the SNP's Stephen Gethins, she must unseat another Remain candidate who has spent years burnishing his pro-European credentials.
Since first arriving in the House of Commons in 2015, he has been set up for big things by his party, almost immediately becoming the SNP's Europe spokesman at Westminster.
Just two months on, Gethins became the first ever SNP member of the Commons foreign affairs select committee.
But in Theresa May's 2017 snap poll, he saw a relatively robust majority of more than 4000 slashed to just two.
That didn't prevent new SNP Westminster leader Ian Blackford from promoting him to his frontbench as international affairs and Europe spokesman.
It's a sign of the party leadership's view of his abilities - with another being how often Gethins can be found representing the SNP on news and current affairs programmes.
On his narrow victory last time out, Gethins said: "That was 2017, that was two and a half years ago. A lot's happened.
"We're bringing over a lot of Lib Dems, a lot of Greens and even Labour voters as well.
"Crucially, we need to stop that Tory-Brexit party alliance and we need to make sure we're sending a Remain party candidate back.
"And as everybody tells you, as Remain United and others have shown in their analysis, I'm best-placed to do that."
He added: "As the only Scottish MP who worked in the EU, who's been working cross-party, who's one of the co-authors of the Benn Act that stopped a no-deal, that's important."
Gethins took over from Liberal Democrat grandee Sir Menzies 'Ming' Campbell, who represented the constituency for 28 years before retiring ahead of the 2015 election.
The big question in North East Fife, which backed Remain in 2016 by 64%, is which pro-European party voters will opt for this time.
Notably, Gethins' pitch is as the best pro-EU candidate, with Scottish independence not getting a look-in in his campaign literature.
Yet for Conservative candidate Tony Miklinski, the scramble for North East Fife is not just a two-horse race.
The local councillor, who won 24% of the vote in this seat in 2017 - nine points behind the two frontrunners - says the constituency meets the definition of a three-way marginal.
Miklinski said: "Last time round, we went from behind 10,000 behind to 3500 - if we do half as well again, we'll win this seat.
"People have got to ask themselves what they want because we're the only party that is honouring the results of both referenda.
"It's difficult to believe the Liberal Democrats can call themselves Liberal Democrats when they've just said that democracy didn't count.
"They've turned their back on the people who voted to leave the European Union and that is fundamentally unfair."
On Boris Johnson, he admitted he had his "doubts" about the PM who he said some voters viewed as the "archetypal toff".
But Miklinski added: "Boris went away and got a new deal. Boris did what he said. He's shown that he's able to do things that other politicians can't."
A distant fourth back in 2017, on less than 10% of the vote, Labour - and their new candidate Wendy Haynes, a local NHS worker - are hoping to do better.
"I think Labour's message is very clear on the Brexit referendum," she told STV News.
"We are the only party that offers a real solution to the mess that the Conservatives have got us into.
"We are the only party that is not taking sides and adding to the division that has been caused in this country.
"We are determined to find a solution that people can get behind."
On the independence question, Haynes added: "Scots, English, Welsh, Irish have traditionally worked well together.
"There's been a lot of intermingling and I think it's a great union.
"But the Labour party's not in the business of coercing people to belong if they really don't want to.
"Labour reforms will convince people that it's good to belong in the UK and that we've got a country to be proud of."
In the historic market town of Cupar, STV met voters across the political spectrum - and among them were a few switchers.
One woman told us: "I'm a sort of Conservative voter but I think I'm going to go for Liberal this time. I was sad they didn't make it last time and I'm not too keen on exiting Britain."
Boris Johnson is another part of the reason. "His heart's in the right place, he just comes over a bit difficult sometimes," she explained.
In Anstruther, sharing a poke of chips with STV's Westminster correspondent Kathryn Samson, two men agreed that while this election should be about more than Brexit, it remains the key consideration.
"One defining issue should not be why a government is voted in," one said.
"In this case, it will be, which I think is wrong."
'I fear the worst in this election, possibly even a hung parliament or something like that.'SNP voter in North East Fife
The other, a pro-independence, pro-SNP voter, added: "There's no way of escaping it. It will govern the way people vote.
"And actually I fear the worst in this election, possibly even a hung parliament or something like that.
"However, it's not going to dissuade me from how I'm going to vote."
And another man, visiting Cupar's farmers' market, jokes that he and his wife were the pair of votes to save Stephen Gethins last time.
"Everybody who voted for him says that they were the two," he said.
Last week's Ipsos MORI poll for STV News suggested a national vote share increase for both the SNP - up 7% from two years ago - and the Lib Dems - boosted by 4% since 2017.
But trying to use such projections to predict if a constituency as finely in the balance as North East Fife could change hands is not one you'd want to stake any money on.
The tighest marginal seat in the whole of the UK , this is the Lib Dems' top election target and they're optimistic about nicking it on December 12.
But they're up against the formidable SNP machine and a prominent candidate - and failure in North East Fife could herald a disappointing election night for Jo Swinson's party in Scotland.