There aren't many projects that could get a harrassed political hack to throw everything on hold for a few weeks this extraordinary Autumn.
But doing a Panorama on Gordon Brown certainly makes the cut. He may never become prime minister. In politics, the unexpected often happens.
There are elephant-traps strategically placed in the Whitehall corridors and man-traps on the streets outside.
But it looks highly likely that he
will, and pretty soon.
The anti-Brown camp are desperately working their way through lists of would-be contenders to take him on but at the moment it feels a little like the sketch about it being time in the war for a pointless sacrifice... Whoever flies out on the mission against Big Broon is unlikely to return.
Yet it isn't just that he is a huge odds-on favourite to lead the country.
Gordon Brown is also a genuine enigma and a huge subject.
Even his enemies, and they are legion, including in the opposition parties, acknowledge that he is one of the few really big personalities and thinkers left in British politics.
His writings and speeches as a red-hot socialist in the old days make you wonder whether, in power, he would rip off the business suit and surprise us all.
Yet, having talked to old friends and his new friends too, including American right-wingers, it seems that he will badly disappoint the left.
In other politicians, you might dismiss this as naked opportunism. No opportunist, though, would bother to read so many books of political and social theory. No opportunist would grind away late into the night trying to remake his language.
The truth is that Brown is a strange, old-new kind of progressive, with a belief in hard work and Christian virtue rooted in the eighteenth and nineteenth centuries, which has now been spatchcocked onto the latest thinking of American conservatives, and resprayed with British Labour rhetoric.
Oddly, Beveridge would have recognised him more easily than most members of today's Labour Party.
So we are probably in for a bit of a shock, and a political surprise.
Watch him wince
Having known and observed him for twenty years, albeit from a safe distance, I am constantly struck by his gusto for ideas and his visceral distaste for much of the soul-baring that seems necessary in modern politics - though he's doing it now.
Can he - will he - fit the consumerist, pleasure-principle, fashionably environmentalist nation we seem to be becoming, and which David Cameron appears to read so astutely?
Or will he be the prime minister of hard times, the granite-faced, gravel-voiced premier of security?
We've talked to a huge range of friends and enemies (apologies now to all whose contribution remains on the digital version of the cutting room floor) and found some funny and some poignant stories, plus some very shrewd analysis.
Don't miss Bob Geldof on what happens when you just feel you have to kiss Gordon Brown; or his university friend on what gives him his urgency.
It has been huge fun to make, this film. And I fear poor Gordon Brown is going to wince when he hears the music chosen by Panorama's wicked producers, who clearly lost their moral compasses years ago.
Panorama: Does it have to be Gordon? was on BBC One on September 24 2006.