It's showtime. The Lightning Bolt, The Beast and The Bad Boy are in town tonight, to renew their rivalry, and reconfirm the identity of the world's fastest man.
They won't need the Olympic Stadium's usual techno soundtrack, and the infantile ramblings of an MC who labours under the impression he is the main attraction.
The track is fast, and the portents for a new world 100 metres record are encouraging.
Intriguing questions remain unanswered, after a day of bluff and double bluff. Is Usain Bolt hiding technical flaws, or indulging in a giant confidence trick? Is the Beast, Yohan Blake, ready to pounce? Can Justin Gatlin become the most infamous Olympic champion of his generation? Even the renegade American, who has twice been suspended for drug offences, acknowledges: "The only person who can beat Bolt is Bolt." This is an athlete, remember, who made history on a diet of chicken nuggets. He won his last Olympic gold medal without bothering to tie his shoelaces.
He knows that his life is defined by less than 30 seconds work, every four years. Absurd when assessed in isolation, yet entirely logical when his social and commercial impact is taken into account.
Alone of the contenders for the Games' most cherished title, Bolt has the ability to levitate an audience. When he emerged into intermittent sunshine for his first-round chores he was greeted by a primal scream of recognition by the 80,000 crowd. They rose from their seats in a strange, instinctive act of homage.
Bolt bounced on his heels like an impatient boxer, and mouthed "number one baby" to the omnipresent TV camera. His race was billed as a sprint, but he gave it the air of a midweek jog around the park by the Old Fartlekians.
He stumbled at the start, recovered his composure after three, faltering strides, and was strolling just after halfway.
The young Briton James Dasaolu, drawn alongside him, even tried to shake his hand as they decelerated after crossing the line. It was a bizarre gesture of respect which underlined Bolt's capacity to give his peers the mentality of spectators.
The Jamaican's time, 10.09sec, was an irrelevance. His rivals were left to read between the lines of his subsequent statement that he has taken a conscious decision not to concentrate on his perceived weaknesses at the start.
We will have an insight into the legitimacy of that particular mind game in this evening's second semi- final, when Bolt will be obliged to counter the emerging American Ryan Bailey, whose qualifying time, 9.88, equalled his personal best. The obvious threat is his training partner, Blake, who prefers a quiet game of dominoes to Bolt's party lifestyle. He ran 10sec dead, easing down 20 metres from the line.
Team GB's Adam Gemili, whose smile lit up the stadium on qualifying, will have another educational experience when he lines up alongside Blake in the semi-final. In the land of the laid-back, Blake has the hunger of a contender. His intensity is convincing, and his nickname adds to the plot.
"When you guys are sleeping at night I am out there working," he insisted. "That's why they call me The Beast. I work twice as hard as everybody else."
Gatlin, the second-fastest qualifier, appears to have the easiest of the three semi-finals. Only Asafa Powell, whose dyed ginger goatee gives him the look of an eccentric uncle, seems likely to stretch him.
A gold medal for Gatlin, a trash-talking testosterone-fuelled throwback who is unapologetic on his return from a four-year drug ban, is athletics' worst nightmare.
There is no contrition – he blames a steroidal cream, applied by a masseur, for his downfall – and no conscience at the damage he has inflicted on his sport
"The critics are going to say whatever they want, probably for the rest of my career," he acknowledges. "I really don't get hung up on who I need to prove myself to. When I wake up, I'm Justin."
That's the problem. Sponsors don't want to be associated with someone who failed in his supposedly sacred duty to be a standard bearer for a new generation of world-class sprinters. They are hardly doing handstands at the prospect of Dwain Chambers, who is in Bolt's semi-final, making the most of the opportunity he won in a courtroom. He won his heat in 10.02, and was immediately ambushed by his reputation.
"Is this race going to be clean?" he was asked by an American writer as he stopped to chat in the mixed zone beneath the stand. It felt like an accusation rather than a question.
"That's not on my mind," Chambers replied with admirable equanimity. "I just want to go out and compete. I've learned at my age to try to set the right example. I'm doing this for my team, my friends, and my family."
Athletics, like cycling, has never allowed the noxious fumes of the chemists to disperse. It needs a pure and passionate 100 metre champion. Any bitterness in his back story will be exaggerated. The sport is struggling to sell itself in an overcrowded marketplace, and it needs heroes.
Bolt was the answer to a million prayers, but no longer exudes a sense of certainty. His is the biggest brand of these Games, but it has been tarnished by sudden failure.
Of course, it will be entirely in character if Bolt flies out of his blocks tonight, and removes 9.58 from the record books. But these are strange times. Beware The Beast.