Three former special forces operatives take scientists on three different missions. They head into the kill-zone of an active volcano, into uncharted rainforests of Papua New Guinea and through the Bolivian jungle.

Rookie Trailblazer Chris leads the hunt for a Caiman after Nick's accident forces him to tap out of Bolivia. In Papua New Guinea, Gary must win passage through local tribes. In Ecuador, a lightning storm pins down Shaun's team on an active volcano.

In Papua New Guinea, Gary ascends 300 feet up into the jungle canopy in search of new plants. In Bolivia, rookie Chris and team go out on the water to confront a giant caiman. In Ecuador, Shaun takes his team up a crumbling landslide to reach the volcano.

As mission time runs out, Shaun and team come under volcanic fire in Ecuador. Gary must stop down when Bat Expert Rob goes missing in the jungle. Rookie Trailblazer Chris must rethink how to catch a caiman when fear takes over his scientists.

With less than 48 hours left, Shaun dodges volcanic bombs in Ecuador. In Bolivia, rookie Trailblazer Chris baits a giant caiman. The Papua New Guinea mission derails when scientist Rob gets lost.

Shaun risks life attempting to place sensors on an active volcano. Rookie Trailblazer Chris wrestles a black caiman. Gary heads 10 miles into a mountain cave to find rare bats.