Nanda Souza

The survivalists go through the uncomfortable moment of meeting their naked partner and begin a race against the clock to find water and a place to spend the first night, protected from predators and the cold of the Argentine Chaco.

While some participants do well at hunting and fishing, the lack of dietary protein begins to affect the actions of others. Psychological pressure and lack of sleep begin to change moods and cause personal conflicts -- and one survivalist has an accident.

The survivalists are surprised by the number of dangerous species inhabiting Chaco. Its rivers are infested with alligators and piranhas, while big cats are on the prowl, approaching the camps at night -- and some worry they can't handle the challenge.

One survivalist scores the biggest hunt of the challenge. Chaco has one last surprise in store: the coldest night yet, pushing participants' calorie-starved bodies on the verge of hypothermia. How many of them will be able to reach the extraction point?

The survivalists evaluate possible strategies to reach the extraction point, and two of them have an intense discussion. Faced again with a lack of dietary protein, one participant executes the riskiest plan of the challenge -- hunting an alligator.