Edge of the Unknown with Jimmy Chin

Sarah McNair Landry, a second generation polar explorer, shares her story of venturing with her brother Eric into the unknown as they aimed to cross the 3300km of the Northwest Passage on kite-skis in winter. Finding themselves overwhelmed by the weather, terrain, and the polar bears, they confronted what it felt like to be "hunted" in an area they had long considered home.

Kayaking legends Ben Stookesberry and Chris Korbuic accumulate together hundreds of first descents in the most dangerous rapids in the world. But one river has left a mark on them. The calm waters of the Lukuga River, in Congo, hide one of the biggest concentrations of crocodiles on Earth. In 2010, they paddled through it with their mentor Hendri Coetzee. That was the last time they saw him.

Alpinist Jimmy Chin is filming in the mountains of the Grand Tetons, Wyoming when a colossal avalanche wipes him out and drags him down a 2,000-foot slope, snapping trees and leaving debris all over the landscape. Knowing that much smaller avalanches have killed experienced athletes before, Jimmy's friends know it's almost impossible that he survived this accident.

"The Holy Grail of surfing," Jaws is a surf break in Hawaii notorious for its enormous, perfect waves. French surfer Justine Dupont wants to beat the best surfers on the planet in the annual competition, but a violent wipeout sends her to the hospital. After months of rehab, Justine wants to risk it all and seek revenge on Jaws.

As he approaches the climax of his career, climber Will Gadd wants to do what many consider impossible: be the first to scale Helmcken Falls, a 430-ft frozen waterfall in Canada known as the world's hardest ice climb. But even with a lifetime of experience, Will fears for his safety as he climbs in subzero temperatures, dodges giant icicles and goes through a near-death experience.

In 2016, elite snowboarder Travis Rice was riding in the backcountry of Alaska, film crew in tow, when the mountain snow spider webbed around him, catapulting Rice into an avalanche. Looking back, Travis reflects on the near-fatal mistake that forced him into unknown territory, sharing how the traumatic event has since shaped his approach to his sport and his life in general.

Legendary climber Conrad Anker and his mentee David Lama want to be the first to summit Lunag Ri, the tallest unclimbed peak in the Himalayas. As they struggle on the side of the mountain, at an altitude of 20,000 feet and glacial temperatures, Conrad grasps for air and suddenly feels a pain in his chest. He realizes he is having a heart attack in one of the most inhospitable places on Earth.

In 2013, elite Kayaker Gerd Serrasolses was on a mission in Chiapas, Mexico, when he almost drowned in an unexpected eddy vortex. After surviving 3 ½ minutes underwater and being revived by his teammates, Gerd shares how the accident continues to shape his approach to balancing risks as a new father and World Champion.

Big mountain skier Angel Collinson boasts the most important achievements in the sport, from first place trophies to best lines ridden. Seeking to cross new limits, she says yes to riding some of the steepest spines in Alaska for a new film. But when she loses control of her skis in the middle of a high-speed descent, Angel starts falling down a 1000-ft slope-and only stops at the bottom.

Alex Honnold became the world's most famous alpinist when he climbed Yosemite's granite wall without a rope. But how did Alex prepare to do the impossible? He and his friend Tommy Caldwell went to Morocco and pushed their limits on equally huge walls, culminating with Alex's ropeless climb up the hardest route. This is Alex's tireless, grinding process to transform a dream into reality.