The teams have reached the halfway point of their journey. For the next leg, must choose whether to travel through Bolivia or Chile - both countries with unstable political climates. Sam and Jo decide to break up their travel with regular breaks, while Jen and Rob have an explosive argument when they get caught up in Bolivia's general election. Emon and Jamiul find work in an Argentinian salt mine, and Dom has a health scare that may require him to pull out of the race.