Competitors move to a new survival zone patrolled by territorial hippos, upending the challenge. Teams must design and build a traditional raffia palm raft. An underdog shocks the competition while a crucial mistake puts a legend at risk of elimination.

The final four teams build four-pronged, fire-hardened spears to skewer fish. One team's spear -- and partnership -- breaks under pressure. Cold, driving rain collapses a shelter. In a frigid elimination challenge, teams battle hypothermia and each other.