The four teams have reached the halfway mark in the 25,000km race to Ushuaia, and with only eight and a half hours between them, the race is on. To reach the next checkpoint - Cafayate in Argentina - teams must choose to travel through either Bolivia or Chile, but an unstable political climate in both countries puts everyone’s journeys at risk. With half the race still to complete, emotions are pushed to breaking point.

First to leave the checkpoint are mother and son Jo and Sam. Jo is feeling the pressure of maintaining their budget and staying ahead in the race, but Sam wants to relax and enjoy themselves more. An unforeseen delay in La Paz gives Sam the opportunity to take control for the day. The duo decide to break up their long journeys with regular stop-offs – including a trip to the spectacular Bolivian salt flats and a stay with an Argentinian farming family, where Sam is prompted to reflect on his close relationship with his late grandfather.

Jen and Rob begin the leg in high spirits – they have started enjoying themselves and are communicating better. But the pressure of getting through Bolivia before a general election shuts the country down boils over into an explosive clash for the couple as they argue over their decision making. Things improve once they reach Salta in Argentina, and the couple finally let their hair down at a penas - a local music and dance venue.

A renewed sense of closeness between Emon and Jamiul prompts Jamiul to ask his uncle more about why he left the family. After Emon opens up, their relationship goes from strength to strength, and they need to draw on that as they face the arduous job of harvesting salt at an Argentinian salt mine in a bid to boost their budget before racing to the checkpoint.

Last to leave the checkpoint, brother and sister Dom and Lizzie’s race is put on hold when Dom has a health scare and their ability to continue is brought into question.

Nothing about this leg is straightforward, with emotions running high, budgets running low and relationships severely tested. Show less