They say it's lonely being a marathon runner. But Guor Marial is in danger of being the loneliest of them all.
He's the man with officially no country, no teammates and no passport.
Marial will be competing under special rules as an "independent Olympic athlete," representing no nation and running under the Olympic flag. His birthplace of South Sudan doesn't have a team at the Olympics.
It's hard running over 26 miles against the best in the world but it is remarkable that Guor Marial will be on the start line in London.
His childhood in Sudan might best be described as horrific. Losing eight of his 10 brothers and sisters in the war-torn country, he was sent to live with his uncle but was captured on route in Sudan and forced to work as a labourer.
He was 10 years-old.
There was plenty more horror through his childhood from beatings by his captors, to being forced to work as a servant. He escaped to Egypt with his aunt and eventually they were taken into the USA as refugees. He now lives and trains in Arizona. His adopted home hasn’t made him a citizen, as yet.
Guor admits he didn't want to run at first. The reason is that 'I have spent most of my life running to avoid being killed. I didn't want to run anymore.'
In his first marathon he ran a fast enough time to qualify for the Olympics. The race through London on Sunday will be just his third ever marathon. Without the experience and quality, he's unlikely to be amongst the medals. Yet.
Guor has been in an unusual position in the Olympic village and has humbled many people around him. He may now be dressed in his smart IOC tracksuit but he only had one pair of trainers until they provided more kit for this race. He'll run in a neutral grey shirt.
He is proud to represent the IOC he says but 'loves the people of South Sudan, and is doing this for them and their profile and for new generations in his real homeland’. Sudan actually requested he represent them, after all he went through in the country after leaving South Sudan. He declined.
I ask him when he last saw his parents, his family.
'1993' he says, 'It is difficult to make contact with them, but I know they will try to travel to watch me on a television, but is 30 kilometres away and the journey is hard.'
NINETEEN YEARS ago. Of course he dreams of being reunited but running this Olympic marathon is his focus right now.
If he needs help getting to South Sudan you imagine the man alongside him might provide it. Brad Poore helped him get to these Olympics more than anyone else and is his one-man support network at these Games. Other competitors have befriended him though, those aware of his story and those fascinated by his tracksuit top, the man with no nation.
Guor will make plenty of new friends when he runs in London - one of the ticketless events that will lead to hundreds of thousands lining the route and encouraging the competitors.
He may not have his country's colours on his chest, but his Olympic debut is not quite so lonely after all.