Portillo gets up close and personal with Alex Salmond
It was a no-brainer that Alex Salmond would be the story of this election.
If he won, it was historic; he would be the first party leader to have won two elections in the history of the Scottish Parliament.
If he lost, it would be a political obituary for the man who had taken the SNP into government for the first time in its history.
But while the notion of making a documentary about Alex Salmond was a no-brainer, just how to go about making something fresh and original took a bit more thought.
Bringing in Michael Portillo immediately changed the nature of the programme.
The thought of the darling of the SNP coming face-to-face with the one-time darling of the Thatcherite right was just too intriguing.
They may not agree ideologically, but it is interesting to see one politician through the eyes of another.
Despite their political differences, Michael Portillo said of the head of the SNP: "Alex Salmond is, to my mind, the only Scottish politician to have made most of his career in Scottish politics who is well known in England, and I dare say internationally.
"I mean I regard him as the outstanding politician not to have come out of Scotland, but to have remained in Scotland."
And with that in mind, we set off filming across Scotland, enjoying the glorious April sunshine, and the feeling of watching a genuinely fascinating campaign.
We spoke to many of those who have worked with, and written about, the first minister; some of them for more than 30 years.
The key question was this: What does Alex Salmond's life and career tell us about the man who led his party into government?
He is a fiercely private man in a very public role, and it is interesting to watch how that dichotomy works. Indeed, the film explores many of the man's apparent dichotomies.
How could the radical young nationalist enjoy working for the Royal Bank of Scotland?
How could he move from party exile to MP and leader in just a few years? And how could a man who quit his party's leadership come back and take them into power?
We were able to watch him close up, campaigning in Glasgow's south side (where it's suggested that Michael's past means he ought to wear a disguise) and in the first minister's native Linlithgow.
Of course, we now know that they would go on to win both seats.
But when we began filming, Labour was ahead in the polls, and it looked as though the Salmond era could be drawing to an end.
Of course, in one way it is only just beginning. So is independence more likely after last week's win?
A referendum is on its way, and as Michael Portillo says: "People in Scotland tell me there's little support for independence.
"But as the recent referendum in the UK on the alternative vote shows, opinion shifts fast. And the first minister's recent landslide re-election shows that he is persuasive."
Portillo On Salmond is broadcast on BBC One Scotland at 2100 BST on Sunday.