Adam, Heather and Sam score a massive protein win, but the trek through Colombia's badlands puts the team at risk. Chris battles a mystery illness. As tension rises, Nathan reveals a secret to his partners. The Proving Grounds send a survivalist home.

A newly formed tribe quickly works together to stalk and kill a caiman. The pressure to trek 40 miles to extraction pushes two teams to make risky migrations. A survivalist is on the brink when medics discover parasites in their digestive system.