It was just after 4pm and Sir Chris Hoy was gently preparing for the greatest sporting moment of his life, riding his bicycle on instinct, almost without thought or purpose.
At 6pm, this force of nature was bantering with press men with all the malevolence of a junior manager at his boss's dinner party. Yet the intervening two hours had witnessed two races that crowned Hoy as the greatest ever British Olympian.
The shark had gorged again on gold. The nicest sportsman had proved himself the most ruthless competitor. The evidence lies in six gold and one silver across three Games.
The transformation in Hoy requires the powers of description of a Robert Louis Stevenson with a nod to Jekyll and Hyde. It is, though, apparent as he swishes past with a brutal efficiency then pulls himself from his bike to engage in intelligent, courteous and relaxed conversation.
Hoy's two hours in a packed, sweating velodrome contained perhaps only seconds of extreme physicality and stress. He reacted in those moments with the instincts, grace and strength of a champion. The hard miles had been ridden in Beijing and Athens and on bikes and hi-tech equipment in Manchester and Newport.
When Hoy's moment came, he knew what to do. He then did it. The win in the keirin event yesterday afternoon could stand as the most persuasive testimony to his greatness.
The semi-final was won cleverly and without fuss but the Edinburgh rider knew that final would present difficulties. The keirin is a race that asks questions beyond the physical. Hoy had the answers.
His moment of truth came about 500 metres away from an historic destination. A sixth gold medal to overtake Sir Steve Redgrave lay just over the finishing line. Hoy – assessing speed, positioning and the form of his rivals – made a decision. He would go for gold. It was a gambit that seemed to be fatally flawed when Max Levy of Germany cruised alongside the Scot then nudged ahead on his outside.
"Max was coming with a lot of speed and I thought for a moment that the dream's over," he said. "But I kept digging and I had the inside line so I could prevent him from overtaking. Once he gets ahead - "
Hoy paused for a moment to consider the horror that moment contained. He continued: "If he had just got past me and he had shut me down then I would have been nowhere – second or third."
Notice the end of that sentence. Consider it. Second or third equals nowhere. This was articulated without arrogance or bombast. It was a statement of the obvious.
Hoy has six golds and one silver. This tally is not a matter of chance. The Scotsman wins. That moment of threat on a bend in the East End of London did not disconcert him. He was energised by the moment. This was a time for fight or flight. Hoy, of course, did both.
He tells it best. "A lap to go, I caught my coach's [sprint coach Jan van Eijden] eye and he was quite animated, jumping up and down and I realised that it was the time to go. I was feathering the throttle a little bit, I wasn't on full gas.
"In the semi. I committed just a little bit too soon and he said: 'Be patient'. But Max was coming with a helluva lot of speed and he almost got past me."
It was then that Hoy saw the danger and reacted almost violently. He kept Levy on the outside, knowing any hint of surrender would have been rewarded in silver or bronze.
The break from 500m now came down to the briefest of sprints to the line. The riders bunched. Hoy was just in the lead and the heaving, deafening velodrome roared in a mixture of hope and fear. "I gave it every last effort. All the gym sessions, all the interval sessions, all the track sessions – that's got me through the last 50m," he said later. The words are dramatic but were delivered softly.
The riders flashed past the line to a clamour of noise and with spectators leaning over barriers screaming and shouting in relief. In the blur of four riders bending their heads in a sort of deference to the finishing line, it was obvious the Scot had won. Levy, brave but vanquished, was second. Simon van Velthooven of New Zealand and Teun Mulder of the Netherlands shared a bronze.
The rituals of winning, so often experienced by Hoy, now were introduced. There was the ceremonial unveiling of the Real McHoy banner that his parents, Carol and David, have carried all over the world. The medals were counted off by the historians: silver in the team sprint in Sydney 2000, gold in the kilometre time trial in Athens 2004, gold in team sprint, keirin and sprint in Beijing 2008, gold in team sprint and keirin in London 2012.
But this was all about a wonderful, pulsating present. Hoy removed his helmet and transformed himself from unforgiving competitor to a smiling, blond knight of the realm, cycling round a cheering velodrome as if he was reprising the scene from Butch Cassidy and the Sundance Kid.
The emotion from the crowd was palpable but Hoy seemed serene, smiling and waving to individual figures in the crowd. There was a hug and congratulations from Sir Steve Redgrave. There were the interviews with every radio station and broadcaster from New York to Newarthill.
The scale of his achievement only came to him later, most noticeably when he made that final step on to the highest point of the Olympian podium. The tears came as they did when he won the team sprint just last week.
"You contain your emotions for so long, you focus on performance rather than the outcome and you try to address every possibility and leave nothing to chance. You look at Vicky [Pendleton] tonight, she was hoping to win and she didn't. It is sport. Anything can happen at any time," he said.
It was the end of the Olympic road but Hoy reflected on the steps and the stumbles to a glorious, historic ending.
"There are so many hard moments when you are doubting yourself in the four years. It is a long time. It is four years of hard work, injury, disappointment. It is a glamorous thing to be a cyclist. You have to put in the hard work. That is why you enjoy these moments," said the 36-year-old.
And is it over? Will Hoy grace the Commonwealth Games in Glasgow of 2014? "I hope so. That is the dream," he said. But then he talked of the sacrifices and the 35 hours of training every week and the demands on his family. "We will wait and see. I am going to have a holiday, a decent couple of months off, reassess things and see where we are," he added.
The Sir Chris Hoy Velodrome in Glasgow would welcome his presence. There are those who will attest with some certainty that an arena in East London was the Sir Chris Hoy Velodrome for one, dramatic, historic evening.