Simone Biles had just performed a horror vault not so much uncharacteristic as unprecedented. Her score of 13.766, on a piece of apparatus where she had mastered moves no rival could contemplate, was the lowest of her Olympic career by far. She grimaced, before being ushered away from the harsh lights of the Ariake Centre by her trainer.
Within minutes, she was withdrawn from the rest of the team final, a decision that not only emboldened Russia to wrest gold from the reigning US champions but raised grave concerns about the psychological state of these Games' greatest global icon.
Those worries would be confirmed in her post-competition interviews with a harrowing intensity. It was approaching midnight in Tokyo when Biles disclosed the full extent of the trauma that gymnastics had created in her mind, describing how she no longer trusted herself, how she felt the joy of the sport had been stolen from her.
Here was an athlete who, through the endless agility conjured by that 4ft 8in frame, had brought joy to countless millions, and yet she could speak only of how much it had made her suffer.
It was a heartrending spectacle, sure to trigger an uncomfortable mental health conversation far beyond the uneven bars or the balance beam. Can sport truly be worth this? Can anything?
Biles had served ample warning that she was struggling with a delayed Tokyo 2020, tormented both by the infernal Covid restrictions and by the yearlong assumption that she would be the one surefire ray of light amid the gloom.
"I truly do feel like I have the weight of the world on my shoulders at times," she had posted on Instagram, not 24 hours before she was due in the arena. "I know I brush it off and make it seem like pressure doesn't affect me. But damn, sometimes it's hard."
This was the first major competition that the American women had lost in 11 years. Much the greater shock, though, was the manner in which their most luminous star slipped from the stage. The suddenness of it made the message she had felt compelled to send hours earlier all the more haunting.
It should have been a moment of quiet contemplation, as Biles slipped back into her tracksuit, accepting she had to abandon an event she had been expected to electrify. But even then, she had a dozen cameras fixed on her. Such is the strain of her life, where gold is treated as a given, even when one fractionally mistimed vault can sabotage it. It is a strain that she has shown signs of finding unbearable.
In retrospect, perhaps these hints were best heeded sooner. A year ago, she had expressed her despair at the Olympics being postponed, conscious of the pain to which she would be subjecting her body for another 12 months.
In an interview only this month, Biles had claimed that the only aspect she would enjoy was the time off afterwards. Here was an athlete restless not for her final international showcase to start but for it to finish.
This protracted, five-year Olympic cycle had been framed throughout by the unspeakable crimes of Larry Nassar, the former US team doctor sentenced to life in prison without parole for sexually abusing hundreds of young female gymnasts entrusted to his care.
It was only weeks after Rio 2016 that the dam wall began to break, with the exposure of an institutionalised code of silence around Nassar. Come 2018, recognising that she, too, had been touched inappropriately by him, Biles finally spoke out and earlier this month revealed she had contemplated suicide.
"I remember telling my mom and my agent that I slept all the time, and it's basically because sleeping was basically better than offing myself," Biles said. "It was like my way to escape reality. And sleeping was the closest thing to death for me at that point, so I just slept all the time."
Against that backdrop, can the sheer scale of the hype industry still attached to Biles be healthy? She had stressed that she was committing to Tokyo purely on her own terms, not in service to the USA Gymnastics culture that failed her so abysmally. But still everybody wanted their pound of flesh.
In an advert for NBC, the US host broadcaster, the narrator declared: "When you are Simone Biles, certain laws just don't apply – like gravity." There ensues a blizzard of flips and twists, before the screen fades out with the message: "The greatest of all time."
That much is difficult to dispute: at 24, Biles has accumulated 25 global medals, more than any other gymnast in history. Of those, 19 have been gold, including four in Rio. But while such a bounty brought expectations of an encore, the hysteria sadly neglected the fragility of the young woman required to cope with it.
Biles, lest anyone forget, retains an astounding resilience. In 2018, she led the US to a world title despite being diagnosed with a kidney stone. Here, too, even after the agony of her premature exit, she spent the rest of the contest cheering her team-mates from the sidelines.
Watching this stark inner conflict unfold, it was difficult not to be reminded of what she had written, three years ago, when she revealed what Nassar had done to her.
"Most of you know me as a happy, giggly, energetic girl," Biles said. "But lately, I've felt a bit broken. The more I try to shut off the voice in my head, the louder it screams."
In the white heat of an Olympic final, that scream reached an overwhelming volume.