High in the French Pyrenees, bad dreams are catching up with Britain's modern pentathletes.
Two of the squad reported waking from nightmares during their altitude training camp at the Font Romeu resort.
"Altitude is already playing tricks on the brain - had a sad dream last night and woke with a tear-stained face," tweeted Heather Fell, silver medallist at the 2008 Beijing Olympics.
Team-mate Samantha Murray continued the trend: "I hate the nightmares I get at altitude - and the bad night's sleep that goes with them."
Nobody can blame them for losing sleep, because the nightmare is becoming a reality. The next four months decide which two of six world-class women will represent Great Britain at the Olympic Games.
Team GB has a superb record in women's modern pentathlon. Since the introduction of the women's event at Sydney 2000, Britons have won four of the nine medals on offer.
They stand a good chance of adding to that tally at London 2012, because this year's squad is the strongest yet. But that also makes it the nerviest yet, as the fight for those two places intensifies.
Days before the squad left for Font Romeu, the final selection trials for the 2012 season took place. Over the course of two days, the women completed all five events - fencing, swimming, riding, and a combined run-shoot finale - in and around their base at the University of Bath.
Now, they wait for the line-up for this year's opening international races - World Cups in the United States and Brazil - to be confirmed, giving the first clue as to who is ahead in the sprint to the Olympic start line.
Freyja Prentice, perhaps the most likely at this point to be selected for London 2012, did not compete at the trials. She is still carrying a slight injury but, by virtue of being the only squad member to have reached the Olympic qualifying standard - at last year's test event inside Greenwich Park, where pentathlon will reach a finale at the Games - she holds an advantage.
"Freyja's almost going to the Games, really," admits Murray.
If Murray is right, that leaves five to fight for the one remaining golden ticket.
On day one of that final trial, Fell swam the 200m course in what she reckoned to be one of her fastest times in a decade. Her Olympic pedigree counts for little now, almost four years down the line. Having had her head turned by media work in the aftermath, only now does her focus appear to have fully come back.
Fell is chiefly up against Mhairi Spence, a Scottish livewire whose mother makes kilts for a living and whose father, according to Spence, spends his working days up to his elbows in samples of norovirus.
Spence's record of World Cup medals last year probably nudges the 26-year-old ahead of Fell in the pecking order, for now. That leaves Murray, Katy Livingston and Katy Burke as the outsiders scrapping to be let in.
Preston-born Murray, 22, was working in a greasy-spoon when Fell won Olympic silver in 2008. Since then she has finished her A levels, spent six months in Paris studying, and grafted her way onto the elite programme in Bath.
Livingston, by contrast, ran the same Olympic race as Fell, arguably starting it as the more likely British candidate for a medal.
The 28-year-old raced to a creditable seventh place but changes to the sport following the Beijing Games, mostly in the name of improving its spectator appeal, caused her a world of trouble. The running and shooting were merged into one "combined event", and air pistols were replaced by laser guns.
"It's been a hard slog. A hard three-year slog, really," Livingston conceded as the selection trials concluded.
"This weekend has been pretty good in general. I'm really pleased with my ride and this is the first year I've had progress in the combined event.
"I wouldn't say I was back yet. But I'm glad I didn't retire [in the face of those struggles], I feel good about what I've achieved. If I miss out, it'll be very close."
Selection results, and the teams for those first two World Cups, take far longer than the two days initially forecast to emerge. Eventually, the following Friday afternoon, the news is posted online.
Prentice, Spence and Fell will go to both World Cups, it is announced. They get the green light for the next stage. Murray will get one chance to impress, in the US. Livingston will go to Brazil.
For Burke, the news is bleak. Her one appearance on the list is as the reserve for the Brazil trip. While the coaches may yet grant her an outing to one of the later World Cups - there are four, then a final - Burke knows she struggled.
"It hasn't been the best," says the Blackpool 22-year-old, frowning. "I was just getting back to fitness. We'll see how it is, but my rankings aren't brilliant. I know I can improve so much on the selection results. My performances last year show that."
The World Championships, in Rome in late May, are the real decider. Three women can go and if you are not on that boat, your Olympic ambitions are either terminated or postponed until 2016.
Even once on the team, there are three women at the Worlds and only two at the Games. The process of elimination is slow, painful and inevitable.
"There's no room for confidence at the moment," says Fell. "It's a matter of every session, every competition, keep performing and putting it in. There is no time to rest. No time to relax about that."