The Peruvian Amazon's aggressive piranha, venomous fer de lance and even poisonous plants test 12 survivalists. XL rookies look to last 40 days while vets try to make 60 and become Legends. Four survivalists will be gone in the first four days.

The Peruvian Amazon. A rich, beautiful rainforest where thousands of species of animals and plants want to kill you. Now, 12 survivalists begin a new XL challenge there -- some going for 40-days, others attempting 60-day legend status.

Steven takes a huge risk when he raids a caiman nest for eggs; Dan and Waz join forces to snare the vultures circling their camp; Amber, Trish and Jen take on a huge project, but tensions could tear them apart.

Three elite survivalists join the challenge; Dan and Waz take on dangerous prey; Amber battles an aggressive caiman to feed her team; Steven's main source of food turns sour.

The Legends put their mark on the challenge; desperate to get food for Steven, EJ creates poison blow darts to chase a much-needed meal; Matt spearheads an ambitious dock build that drains Dan's strength; Jeff adds to the tension on Amber's team.

Jeff struggles to keep food down; Trish and Amber hit a breaking point; Matt, Dan and Waz cross piranha-filled waters and score a big kill; EJ and Steven's new camp is stalked by a jaguar; a survivalist leaves their group to go solo.

With Amber gone, Trish and Jen must fend for themselves; Amber joins forces with Steven and EJ. A distant fishing hole means a punishing journey for their next meal; after a huge food win, Dan and Waz make a high-risk choice.

Desperate for food ahead of their Day 40 extraction, Jen pushes Trish to hunt new territory. Dan, Waz and Matt corner one of the Amazon's apex predators, a six-foot caiman. When Trish and Amber's paths cross again, tensions re-surface.

Pushing past day 50, the final six survivalists come together as one group, but must scramble to expand their shelter; the Amazon unleashes a bee swarm and a torrential storm; a knife accident threatens a survivalist's challenge.