Four groups of elite action-adventure athletes are followed on four unique, never-before-accomplished missions around the globe. As the athletes venture up and down mountains, down rivers, and across oceans, they rise to meet life-threatening challenges that test their decision making and athletic capacity. The series explores the marvels of nature's beauty amidst the present-day risks of climate change, deforestation, and the perils of human industry in these remote and beautiful parts of the world, while celebrating the inspiring feats of human achievement. Taking part are snowboarders Jeremy Jones and Elena Hight, and skier Griffin Post; kayakers Ben Stookesberry, Nouria Newman and Erik Boomer; climbers Emily Harrington and Adrian Ballinger; and surfers Ian Walsh and Grant "Twiggy" Baker.