Election night on Thursday could bring us some surprises.

Polls indicate the SNP are set to form a second majority government mostly through constituency seats. You could be forgiven for thinking these results could be uneventful but across the country there are key seats which it is too close to call.

These span the length and breadth of the country.

Here are five seats to keep an eye on:

In 2011 Scottish Labour's Elaine Murray was re-elected to Holyrood after topping the Dumfreiesshire poll with 39.6% of the vote, 9.9% more than the Scottish Conservatives in second.

The referendum has completely altered the likely outcome of the seat. Now it looks sets to be a close fought contest chiefly between with the Scottish Conservative candidate Oliver Mundell and the SNP's Joan McAlpine.

At the 2015 general election in the geographically similar Dumfriesshire, Clydesdale and Tweeddale constituency it was neck-and-neck between the parties' two candidates with David Mundell (Oliver's father) winning with just 1.5% more votes than the SNP candidate.

On the night Dumfriesshire's results will give us a strong indication if there was any validity in the theory that people who voted No in the 2014 independence referendum are switching allegiance from Labour to the Tories.

Will the "unionist alliance" which Mundell has called for form?

The constituency was a close run contest at the last election and it looks set to be so again.

In 2011 the SNP were victorious in the seat with just 29.4% of the vote. Previously the seat was held by the Scottish Liberal Democrats but they finished third behind Scottish Labour after their vote share collapsed following the 2010 agreement to form a coalition with the Conservatives at Westminster.

Scottish Labour believe that this could be their best hope of winning a constituency seat anywhere in the country on Thursday.

Like Dumfreisshire for the Tories, Labour's hopes are pinned on Unionist voters switching to Labour to keep the SNP out of office.

If they fail to convince voters in Edinburgh Southern to do that then it would be a real possibility that Labour would end the night with no constituency seats.

The Scottish Greens have pinned most of their election night hopes on the regional list.

In Glasgow Kelvin however the party are campaigning to pip the SNP to the post on Thursday. Their candidate is the party's co-convener and most well known public figure, Patrick Harvie.

The party did not field a candidate in Kelvin at the last election but in the 2012 local government elections highlight that the areas of the constituency contain above national average support for the party. The Hillhead council ward returned the Green candidate with 17.62% of first preference votes compared with just 2.31% across Scotland.

With the Greens expected to improve on their 2011 vote share nationally this constituency could hand the party their highest share of a constituency vote anywhere in the country on Thursday.

The Greens' only MP Caroline Lucas spent a day campaigning with activists in the constituency:

Scottish Liberal Democrat leader Willie Rennie has said he expects his party to "grow" at this election.

To do so they need to win seats like Edinburgh Western.

Before the constituency's boundaries were redrawn and renamed the party was victorious in the old Edinburgh West seat in the 1999, 2003 and 2007 elections. On each occasion the party polled impressive votes shares; 36.46%, 43.34% and 39.4%.

To begin to turn back the electoral tide it is in seats such as this which the party must grow in. At the beginning of the contest the hopes of their candidate Alexander Cole-Hamilton were slim but the party has grown in confidence of its chances.

Lib Dem director of communications Adam Clarke was highlighting the shortening betting odds for success:

The party has also placed a lot of campaigning time and money into the contest. UK Lib Dem leader Tim Farron has even made a camapign visit:

If the Lib Dems do "grow" as Rennie has forecast then it could start in Edinburgh Western.

The fallout from the Alistair Carmichael 2015 leak controversy hangs over the election.

At all previous four elections to the Scottish Parliament the Liberal Democrats have triumphed here. The SNP however sense that they can unseat them here in their northern outpost.

In 2011 the SNP trailed the Lib Dems by 10% here but with the post-referendum political upheaval and the Carmichael saga the SNP have set their sights on conquering Orkney.

Nicola Sturgeon joined the constituency campaign in an effort to galvanise the local party efforts. If they are successful in doing so then Donna Heddle will become the Nationalist's first elected MSP or MP for the islands.