Dave Nessia

As the challenge comes down to the final four participants, Chilko Lake continues its onslaught on those struggling to survive.

With only 3 left in the competition, the participants struggle to claim the $500,000 prize. While some continue to deal with the mental game, a new predator threatens a survivalist's longevity.

Prying wildlife continue to stalk the remaining competitors, threatening their food and their safety. One participant finds a grizzly too close to home, while another is unprepared when their health takes an unexpected turn for the worse.

While some participants continue to work on new ideas to gain calories, others hunker down to try and last as long as they can. With the struggle to procure food this late in the competition, the threat of being pulled out becomes all the more real.

As they reach a month in the wild, winter weather raises the stakes for each participant. An unwavering grizzly causes one competitor to prepare for battle, and another's desperate attempt for food suddenly turns life-threatening.

The mental toll of isolation begins pushing participants' psychological boundaries to their limits. One survivalist gets caught in an off-putting standoff, while the increasing emotional cost of solitude afflicts another.