Ben Fogle embarks on an epic South American adventure from the Equator to the Tropic of Capricorn, supported by a team of deserving heroes who help him take on the world's toughest environments. His journey begins in Ecuador, where he leads his team through the Avenue of Volcanoes to the summit of Mount Chimborazo, the closest point to the sun on Earth. Meeting Ben at the Equator and climbing at high altitude, community worker Sandra is in trouble from the start, while lifeguard Sophie and aid worker Vanessa suffer the early signs of altitude sickness. There's the agonising prospect that their extreme dream could be over before it's properly begun.