A headline-generating, column-filling, attention-grabbing, outsized personality. He attracts loyalty from some, opprobrium from others.

And, yet again, he is back.

The prime minister before last was never likely to dissolve into the ether, gently fade away and disappear. And he hasn't. This return to the fray isn't voluntary or even welcome from his perspective, relitigating as it does his character, his judgment, his believability.

Here is a sense of the specifics the questioning is likely to get into.

Is what we will hear from him likely to change your mind about Mr Johnson? That will ultimately be your call.

But my hunch is for most people beyond Westminster - and most people here too - it won't.

So why does it matter? It matters because it has the potential to finish him politically. But, as my colleague Helen Catt puts it here: "there are a lot of ifs in this process."

Just one of them is proving to a cross-party committee of seven MPs, which includes four Conservatives, that he intentionally misled parliament.

Proving intent, on the basis of what we have seen, so far at least, seems difficult. Arguing he was "reckless" in his testimony to the Commons is an arguably more subjective call - and so, potentially, a more plausible case around which the committee could unite.

Mr Johnson will vehemently deny both.

But it is possible that MPs in general, and Conservative MPs in particular, may one day have to decide if they want to try to finish off Mr Johnson, or not.

What, then, are the wider political consequences of all of this?

There's a good reason why Rishi Sunak picked Tuesday morning to sit down for a long interview with BBC Breakfast. The chance to scrutinise a prime minister at length is a journalistic opportunity few news programmes would turn down.

But leaders pick their moments carefully before subjecting themselves to these encounters. And Mr Sunak and his team feel he has had a good few weeks:

A deal with the EU over Brexit. A deal with France over migrants in small boats. A deal with America and Australia over defence.

A prime minister, as they would see it, who is serious and business-like, gets his head down and gets stuff done.

Who on earth could they be drawing a contrast with? And better to say all this stuff before the guy before last is back on stage again.

In my job I get brief glimpses into how our prime ministers operate: their quirks and traits, as well as their beliefs and policies. When it comes to character, the contrast between Boris Johnson and Rishi Sunak could barely be more stark.

The instinctive flamboyance of Mr Johnson, the quotable camera-magnet, the colourful private life, the never-ending questions about his integrity. The instinctive caution of Mr Sunak, scrupulously careful on camera, a disciplined, teetotal, man of faith.

And Mr Sunak, early polling evidence suggests, may be slowly resuscitating his party's image. He, some polls indicate, is more popular than his party - but both are, very steadily, ticking up, albeit still miles behind Labour.

Enter next, thumping onto the table, this scrapbook of a chaotic Conservative past. The country reminded of the catalyst that brought a landslide-winning prime minister crashing down to earth - and the backbenches - in just a handful of years.

Conservative MPs, witnessing these contrasting characters, reminded again of what they did, bringing Mr Johnson down.

A first name-terms leader who fired up the party and assembled an improbable coalition, taking in Workington, Wokingham and West Bromwich. Did they make a terrible mistake getting rid of him?

Some think they did. Others think all this proves it was the right call.

One minister tells me he reckons Mr Johnson's supporters are down to a "Taliban of ten, maybe twenty. He no longer commands the Conservative plains like he did."

But he has been apparently down and out before, only to manage a revival. However unlikely a return to the leadership, this week is a reminder to his party and the country, that Mr Johnson has never quite gone away.

And he is not likely to just yet. The latest of many episodes in the Boris Johnson box set drama is starting.