For nearly 70 years Orkney and Shetland has been a Liberal stronghold.
Westminster's most remote constituency was the domain of Jo Grimond, the leader of the party for a decade.
Alistair Carmichael has served the constituency for the past 16 years.
But the safe seat has become a marginal, with the Scottish National Party surge of 2015 taking them within 817 votes of gaining all 11 Liberal Democrat seats in Scotland.
And the only survivor of the rout has a problem as he seeks re-election.
Mr Carmichael was Secretary of State for Scotland in the coalition government.
During the 2015 campaign he tried to discredit the SNP leader Nicola Sturgeon with a leaked memo suggesting she secretly wanted David Cameron to win the election. He then lied to cover up his role.
When the truth emerged, four of his constituents mounted a legal challenge to force him to stand down as their MP.
They raised more than £200,000 to bring the case to court. Mr Carmichael survived, but two judges agreed he had told a "blatant lie", and ordered him to pay his own legal costs.
The damage to his reputation could be an election issue.
He told Sky News: "To be in politics is to be judged. I've always accepted that.
"I think people here are fair-minded people who will judge me not just on that one incident, but on my record of getting things done and helping people here in the isles for 16 years.
"I regret any damage I did to politics and my party. It's taught me that I'm never getting myself into that situation again."
Two of those who brought the case told Sky News that in an island community, personal integrity is even more important.
Fiona Grahame said: "It was a smear, and then he lied to cover up the smear that he had perpetuated. We're all quite close to one another. We meet each other in the street. I live quite near Alistair. So for him to do this and be so dishonest was really quite appalling."
Her colleague Tim added: "You have no right whatsoever to complain about politicians being dishonest if you're not prepared to hold them accountable at the absolute point where you're able to do so."
Mr Carmichael believed the legal case was an attempt by nationalist supporters to oust an elected MP, and Mr Morrison admits being a member of the SNP.
The party's candidate in this election is 26-year-old Miriam Brett, who grew up on the Shetland island of Bressay, and who has worked as an SNP economic adviser.
She demonstrated her local credentials by playing fiddle in a traditional music session in a Lerwick pub, but one of the reasons the SNP failed to win the seat last time was because Orkney and Shetland are among the most pro-union parts of Scotland.
Ms Brett told Sky News: "What this campaign is about for us, is creating a strong, principled and consistent opposition to an increasingly reckless agenda at UK government level and I think the SNP's record on that is incredibly strong."
With Labour, Conservative and UKIP candidates trailing well behind in the 2015 election, Adam Civico, the editor of the Shetland Times, thinks pro-Union voters may get behind the Liberal Democrat candidate.
He said: "From speaking to people you get the impression that yes there is going to be tactical voting. I think there's a good number of people around who will perhaps support Alistair Carmichael simply because they don't want the SNP to win."
There is also an independent candidate, who is in favour of independence - for Shetland.
Some islanders would like to see greater autonomy such as that enjoyed by their neighbours in the Faroe Islands. Shetland is closer to the Faroes and to Norway than it is to Edinburgh.
:: Also standing for election in the Orkney and Shetland constituency are: Jamie Halcro Johnston for the Conservatives; Robina Rendall Barton for Labour; Robert Smith for the UK Independence Party; and independent candidate Robert Smith.
:: And don't forget to watch it on Sky News: The Battle For Number 10 on Bank Holiday Monday, 29 May, at 8.30pm.