LONDON -- Eventually, it all became too much for Laura Muir. As she headed toward waiting reporters in the bowels of London Stadium she stopped and turned her back. The great British hope needed to compose herself and wipe her eyes, and was comforted by a team official.
Roared on by a partisan crowd through a dramatic World Championships 1,500-meter race moments earlier, the 24-year-old missed out by a fraction of a second as Caster Semenya beat her to the bronze medal on the line.
Kenya's Olympic champion Faith Kipyegon and America's serial success Jenny Simpson claimed gold and silver ahead of them, with the winning time 4 minutes, 2.59 seconds; the first four women were separated by a total of just 0.38 seconds, but that was no consolation to the Scot.
"I have had quite a lot of them [lowest moments] so far," said Muir, who had been one of the faces of the event but was left still searching for her first medal on the world stage.
"I thought Glasgow in the Commonwealth Games was hard [she finished 11th in 2014], last year in Rio was hard [she finished seventh at the Olympics], and now this ... It's hard, I can't say anything more. It's gutting."
It wasn't supposed to end this way for the veterinary student. Muir, who ran the fastest women's 1,500-meter time in the world last year, looked in good shape for much of the race, too, apart from getting boxed in twice by Simpson with 600 meters to go. She led early and then made a push for the front again as the pace quickened in the final lap.
"I executed the race plan like I wanted to and in those final few meters it wasn't in the legs," she said. "I was fifth in the last worlds, fourth this time around -- hopefully third time lucky.
"This year I did have a bit of a setback, but saying that I came back from it really well. There is a lot more I can do."
That setback came in June, when Muir lost the best part of three weeks' normal training with a foot stress fracture, and she wondered later whether that may have made the difference between fourth and the podium.
But she has not got much time to dwell: The ambitious athlete has also entered the 5,000 meters and the heats start on Thursday. Muir admitted she was less optimistic about her chances there, given she has raced the distance only twice in her career, but would not be burdened with regret.
"I ran as hard as I could right to the line and there was nothing I could have done about it when they came past me," she said. "I gave myself the best chance I could and I just wasn't strong enough the last 10 meters.
"I didn't look up at the screen or anything because I knew that regardless of what I saw I was going to run as hard as I could. Even if I had looked up and seen her [Semenya] coming, I wouldn't have been able to see anything differently."
So Britain's search for a medal-winning star to succeed Jess Ennis-Hill and Mo Farah as the nation's next track icon goes on.
Muir has the potential to fulfill the role and she has time on her side -- silver-medal winner Simpson, 30, is six years her senior. The way she regained her composure after twice breaking down postrace spoke to her mental strength reserves, as did her continued refusal to be drawn into any debate about the fairness of racing against Semenya.
She will need that resilience to move on from this bitter setback, and to process the way the early chapters of her narrative will be dominated by disappointment rather than golden celebrations. Muir wouldn't be the first athlete to use the dejection from failure to drive her to greatness. "Fourth," she said, "that says it all." But only for now.