Presenter Ben Fogle, Olympian James Cracknell and Hollywood actor Jonny Lee Miller come together to run the London Marathon - part of their training for the race to the South Pole. But after less than expected results, the team start to fracture and then Jonny pulls out due to work commitmnents, leaving Ben and James in desperate need of a third team mate. With the race start only months away, they hold a public selection weekend and start to whittle down the hopeful applicants to the final few. After more rigourous testing, they finally select Dr Ed Coats, a 27-year-old gynaecologist from Bristol. But the team have a lot of catching up to do, and after a week of hell on a glacier in Switzerland, where they finally learn to work together as a team, all seems well - until Ben discovers he has a potentially lethal tropical illness that could stop them in their tracks.