On June 24, 2010, a first-term prime minister who'd won a thumping election victory two-and-a-half years earlier was cut down by his own party, without warning, in one of the most seismic events in Australia's political history.
As Kevin Rudd gave his farewell press conference later that day, doggedly listing his achievements, the tears seemed close. That evening supporters gathered to commiserate at The Lodge and he spoke a second time, thanking staff.
But Lachlan Harris, then Rudd's media chief, recalls him using a line that he hadn't used when the TV cameras were rolling. The statement was a small, ticking time bomb - "We"ll be back".
The night turned into a raucous party. "We all got drunk," says Harris. "We threw Rudd in the pool, it was a celebration of the Rudd government rather than just a wake, though there were moments of real sadness."
But Rudd's seeming throwaway line lodged deep in Harris' memory. "It stuck in my head. It wasn't said as in 'I'm going to be back next week', but there was just a steely determination there to return. He meant he would be back as PM. The significance of that statement never occurred to me until the day he actually came back."
If Rudd's friends underestimated his unstinting resolve to remedy the wrong he'd suffered, so, too, did his enemies. "I think many hoped and expected that I would just roll over and die," says the Prime Minister grimly, as we motor down a Melbourne freeway in the back of his Commonwealth car at the end of the first week of the campaign. "But I'm made of much sterner stuff than that. I'm made of sterner stuff."
He switches tone rapidly, as if catching himself. "So what do you learn from all this? I think it's just resilience ... Teaching resilience around our country, it's ... so important."
The flag fixed on the bonnet of the car flutters in the freezing wind. At his feet lies a plastic lunch box containing an apple and raw carrot sticks. He seems tired, tense, the voice almost a monotone, arms crossed and gazing mostly straight ahead. It's a strangely flat version of the man the media pack had seen half an hour before, giving a rousing stump speech for the local candidate in the lower Dandenong hills.
No, he says, he didn't decide to seize the prize back from day one. "[But] I felt very much as if work was incomplete. Things I had set out to do had not been completed, at a number of levels."
He denies nurturing a sense of injustice, denies - in the face of an avalanche of journalists' anecdotes to the contrary - undermining his successor, Julia Gillard.
"I'm actually driven by a sense of purpose," he insists. "I try and look to the horizon, around the next corner ... the next steps that have to be made so that this country doesn't fall behind."
What he doesn't articulate is the quality highlighted by all those who've had extensive dealings with him: the burning self-belief that kept him going through that political Gethsemane, on and off, for nearly three years.
A senior caucus member says he was stunned when Rudd turned up later in Parliament on the day of his necking in 2010. "It f---ing shocked me. I couldn't do what this guy's doing, I couldn't even get out of bed given the position he was in. But he's an enigma, even to his colleagues."
After the 2010 election, where he says he was drafted in to help out "the government of the time", Rudd joined Gillard's frontbench as foreign minister. But in early 2012 he was goaded by her lieutenants into declaring an ill-fated and ill-timed challenge.
"They wanted to bring it on, thinking they could kill him," says outgoing former minister Martin Ferguson, now a Rudd ally. "It was an orchestrated strategy."
Asked how he survived the barrage of abuse at the time from some of his frontbench colleagues, Rudd shoots back: "Water off a duck's back."
In March this year, with Gillard's polling still in the doldrums, Simon Crean tried to trigger another tilt by Rudd at the crown. The caucus numbers weren't there and Rudd held off. Most around him lost heart.
"Everybody, frankly, lost faith, even his closest lieutenants, your Anthony Albaneses, your Chris Bowens, they all thought it was over after March," claims a member of the inner circle. "But Kevin just kept the flame alive. That's the story of Kevin, this guy who never lost faith in his ability to return."
Peter Beattie, the former adversary and one-time Queensland premier hauled back to boost Labor's prospects in the Sunshine State, says "the fact that Kevin Rudd has come back is a clear sign of how tenacious he is. Love him or hate him, that's real guts."
None of it surprises brother Greg, three years his senior, and raised with Rudd on the tenanted dairy farm where they spent their primary school years.
"Kevin is one of these sorts of characters who's got so much fundamental belief in himself, that what he is trying to do is good and worthwhile, that anyone who doesn't have 100 per cent belief in him he finds it difficult to appreciate their point of view," says Rudd the elder, who's having his own tilt at the Senate as an independent.
But he adds, "I've never understood why people, and Kevin is one - who are supposed to be Christians - have this sort of 'you're either with me or against me' attitude on a lot of things."
Few Australians wouldn't know the Prime Minister's backstory by now. The sickly kid growing up on a dairy farm, youngest of four, extraordinarily bright, close to his deeply religious mother Marge, turfed off the farm after his father died, and then months of disruption, including a couple of nights sleeping in the family car, before finding his feet at Nambour high school.
He went on to study Chinese at the Australian National University, a startling choice for a boy from rural Queensland in the days when only a minority of teens in that state got to year 12. He joined the foreign service, went to China, and became right-hand man to then premier Wayne Goss before winning, on a second attempt, the federal seat of Griffith in 1998.
What clues does this childhood give us to the real Kevin? Maxine McKew, recruited by Rudd to dislodge John Howard from Bennelong in the federal election of 2007, says "you have to understand the deep provincialism and insularity of country Queensland in the '60s and '70s to understand the scale of what Kevin Rudd achieved".
The rock in Rudd's life, say insiders, is his family. Daughter Jessica is a huge asset on social media. Son Nicholas, dubbed the "Kevin whisperer" by the media pack, is travelling with his father as part of the tight-knit strategy team on the road. And youngest son Marcus is volunteering out of Melbourne campaign headquarters. Wife Therese Rein, who presides over an international business empire, talks with him "virtually every day, about anything and everything, wherever she is in the world and wherever I am in the world", Rudd says. "We Rudds move together."
Some see it as further evidence of Rudd's tendency to bubble-wrap himself only with those he trusts deeply. A senior colleague says "he is incredibly close to all of them; it's unusual in politics, where, let's be frank, there can be quite a lot of dysfunctional families".
"Kev-in! Kev-in! Kev-in." Preschool teacher Danielle Goldsmith whips her four and five-year-old charges into a frenzy of excitement as the big white car with the C1 number plate sweeps up to Langwarrin Park Primary School in south-east Melbourne.
Rudd stoops to chat briefly, then charts a carefully choreographed course through classrooms and corridors to the school hall, where he tosses off a few chords on the piano for the band. He's a master at this, turning obligingly for the picture opportunities, pausing for the "selfies" that the kids and even some teachers are clamouring for.
Rudd's electoral appeal is irrefutable; it's the reason he's back. But many of his colleagues are still at a loss to explain his "X-factor" with voters.
One ventures that he's "not seen as a politician, he's a little choir boy, but he also has a gravitas about him".
Another believes he "comes across as a bit of a dick and people actually like that, awkward, a bit goofy, a doofus in terms of his language".
A third theorises that "it's kind of your dad trying to be liked at a party. I think people kind of warm to it, the dorkiness, the wanting to be loved and the faux-folksiness."
Deputy Prime Minister Anthony Albanese, now pivotal in Rudd's praetorian guard, offers the more white-bread explanation that people think he is "passionate about making a difference".
But how to reconcile the many faces of the public Rudd with the private Rudd? How to square the driven visionary seen by loyal staff against the raging narcissist described by some former leading members of his frontbench? How to take the family man and set that alongside the person described by writer David Marr in his landmark Quarterly Essay of early 2010 as someone with "rage at his core"? How to incorporate the man who once invoked the parable of the Good Samaritan when writing about asylum seekers with the architect of the PNG solution?
Where to find the authentic Kevin?
Adverse stories are legion: of his deep-freeze treatment of those who displeased him, tantrums, a disregard for the senior public servants he kept waiting in corridors, of talented but too-young advisers, of the ministers who could not reach him through the whirlwind of activity engulfing his office.
"It almost got to the stage there for a while where everyone had to have a Kevin story. It was a bit like Vietnam; if you didn't have a story you couldn't have been there," says one senior MP, who is over the name-calling. But he believes caucus and cabinet collectively failed, not just Rudd.
"We were very inexperienced, we had been out of government four terms, and you have to learn to manage your leaders."
He has friends, inside and outside politics. Among the closest is Catholic academic Father Frank Brennan, who says he's "been up and down many hills" with Rudd. Brennan talks of Rudd's "very strong sense of vocation but he's also got an intense personal sense of ambition and competition".
McKew, who counts herself an enduring friend, describes him as "good company, extremely engaging, a smart bloke who is curious about all things". She concedes he "can appear to be remote but often it's because he's mentally downloading a lot of material".
But a caucus colleague who's in neither the Gillard nor the Rudd camp says: "There is a superficial warmth. But I read people, not books, and there is something that's always missing." Another calls him "confected".
Harris says: "The people who really love Rudd grossly exaggerate his strengths, and the people who really hate him exaggerate his weaknesses. He's very determined and very intelligent and that has some prickly edges to it. The closer you get to Rudd, the more you see the prickly edges. But if you're a punter, and just want a strong economy and decent country, you just want the determination and intelligence. That's what people around Rudd have to accept and get along with."
Few believe Rudd has come back into the prime ministerial saddle a fundamentally changed man. But those around him believe he has absorbed some lessons from his first tumultuous years in the top job. "It's taught him he's got to try and bring people with him," says one long-time ally. "How well is he doing? Pretty well, though he does sometimes remind me of someone who has been in a major car accident and is learning to walk again."
Rudd blames most of the chaos of his first term on the global financial crisis. "It was like having two full-time jobs to do at once," he says. "The first [the GFC] had me at the absolute centre of it, dealing with heads of government around the world, every day, preventing this thing from just exploding everywhere.
"What do you learn from all that? ... You learn more about separating out the important from the unimportant [and that] in a normal environment, it is much better to have ministers doing it and delegate."
He says he's given no thought to his personal fate beyond the election. No one else claims to know what's in his mind, or how long he'd stay. A victory would be the sweetest vindication of all. A narrow loss, the more likely outcome, would earn him the grudging gratitude of a party that would otherwise be facing annihilation. There is only one question in the minds of ALP campaigners at the moment: "Can he get through on wanting it and the will?" says one. "The answer we will know in three weeks."