They will begin their final journey from the same place, waiting in the call rooms beneath the steeply rising stands of the London Aquatics Centre. Then their paths will separate once again; Tom Daley will turn left and walk down to the deep blue of the diving pool, Rebecca Adlington will turn right and make for the blue and white blocks that squat at the end of the swimming pool.
For four years the teenage diver from Plymouth and the freestyle swimmer from Mansfield have been preparing for these moments. For much of the time it has been a very public preparation, some of that sought, a great deal imposed and both have had some truly testing moments to overcome, inside and outside of their sporting environments. Daley, in particular, has had to deal with the death of his father Rob, the man who 11 years ago spent £25 so his eager young son could have his first diving lesson.
The lives of Daley and Adlington have changed immeasurably since the Beijing Olympics. Daley captivated the Chinese from the moment he arrived at their Games, a 14-year-old, and Britain's youngest Olympian for 48 years. Adlington slipped into the Water Cube, the spectacular venue for the aquatic events, almost unnoticed. A week later she was one of the most recognisable figures in British sport.
It is Adlington who is already assured of sporting greatness. Whatever happens tonight in the 400m freestyle and in Friday's 800m – her signature event – she is already the best swimmer this country has produced. It has not though brought riches. There have been rewards but nothing to make a Premier League footballer stir from beneath the duvet.
"I'm not an athlete who wants to do everything they can to raise their profile," said Adlington in the build-up to London. "It's not about that – it's about my swimming. It's not about making lots of money."
Those around British swimming have nothing but praise for Adlington, particularly the manner in which she recovered from her post-Games mental struggles. Her coach, Bill Furniss, estimates she has missed a maximum two days of training in the last year. Daley's devotion to his training regime has been openly questioned – an accusation resoundingly rejected by his agents. Alexei Evangulov, Britain's Russian performance director, accused Daley of devoting too much of his energies outside the diving pool. The pair have since made up. Evangulov now claims too much of it was made in the press.
Daley, or rather Team Daley, are more commercially active than Adlington. The 18-year-old has deals with Mini, Adidas and Nestle, his own website and TV channel and while of the two he is the higher earner it is also nowhere near the level of a leading footballer. This is about six figures, compared to the footballers' seven.
That will change and dramatically so should he win gold either in tomorrow's synchronised event with Pete Waterfield or in the individual event next week. After competing tomorrow Daley will return to the British diving camp in Southend in a move designed to distance him from the Olympic hype.
He faced the media at the Olympic Park on Friday, along with Evangulov, Waterfield and two other British divers. It was a one-man show. Questions were directed at Daley from Canada, China, Norway, the US. And he answered them all as comfortably, even one about his grooming habits.
Earlier this year he had been equally impressive in dealing with the media after a disjointed performance in the test event in London. That accompanied Evangulov's attack but Daley dealt with it all. He is a polished performer; 18 going on 28. Yesterday he was treating his 360,000 followers on Twitter to pictures of his part in the athletes' parade at the opening ceremony. Adlington is another twitterer – 67,000 followers – but has quietened down. She seems less happy with the attention – understandably so given the abuse she has suffered through Twitter.
Her performance suffered in the couple of years after Beijing – she was reduced to tears after a poor swim in the 2010 European championships. Adjusting to her new life – she was 19 in Beijing – was a bigger challenge than the one she is used to in the pool. Daley and Adlington's paths rarely cross. It is only at an Olympics or world championships that they find themselves together as part of a wider British team. Daley is in the form of his life going into tomorrow's dive – he earned two perfect 10s in winning the recent European championships – but the gold medal remains Qiu Bo's to lose. The glimmer for Daley is that the Chinese teenager has wobbled under pressure before, a pressure that seems to have no bearing on Daley.
This is what unites them. Adlington too seems immune to the pressure in the pool. They are different and they are the same. Tonight Adlington will be in that call room, tomorrow Daley, two different journeys with the same destination in mind.
Recipe for Olympic success
Two golds were won at Beijing, there's no reason why Britain can't aim for three this time but equalling their record four-gold haul may be a stretch.
A busy week at the Aquatics Centre will conclude on Saturday. Liam Tancock holds the world record in the 50m backstroke, but it isn't an Olympic event, so catch him in the 100m backstroke heats and semis today, and hopefully the final tomorrow. Fran Halsall and Ellen Gandy have a decent chance of podium finishes in tonight's 100m fly final.
The wow factor
Missy Franklin, aged just 17, last year set a world record in the 200m backstroke. The final is on Friday.
British swimmer James Goddard calls Michael Phelps the "greatest athlete to ever walk this planet."