Running Wild with Bear Grylls - Season 4

Actor Joseph Gordon-Levitt tackles Kenya's unyielding terrain with Bear Grylls. Dropped into the elements from a helicopter, Joseph and Bear navigate a perilous rappel, milk a camel for needed hydration, and ascend a massive rock dome that tests Joseph's fear of heights like nothing before. As the duo battles a crocodile for the remains of a water buffalo that is their only hope for dinner, Joseph details his rise to fame and his efforts to honor the memory of his beloved brother.

Actress Keri Russell joins Bear on an epic journey to the Canary Islands off the coast of Africa. After battling the dangerous, rolling rocks of a massive volcano, the duo descend into a mysterious canyon where they source a meager dinner of undigested seeds from a pigeon carcass, and test their luck with a grappling hook to escape the towering canyon walls. Later, after a cringe-worthy breakfast of crickets, Keri and Bear make a daring escape from a mountain peak using a paraglider. Along the way, Keri reveals her path to fame, her love of family, and the playful struggles of co-starring alongside her husband. .

Bear takes Lena on the ride of her life as they paramotor deep into the remote Spanish wilderness. Continuing on foot, they traverse a towering, razor-thin ridge before a dead-end forces a harrowing rappel. After securing a dinner of bone marrow from a goat carcass, the two must cross a lake using a makeshift raft as an unexpected storm wreaks havoc. As they battle the elements, Lena grants us exclusive details of life on "Game of Thrones," her rise to stardom, and her battle to overcome depression.

Dropped from a helicopter into unyielding terrain, Don and Bear get creative with a deer antler to cross a raging river, rappel a massive cliff, and attempt a commando-worthy climb to the top of a towering railroad bridge. But the discovery of a rotting porcupine carcass, which Bear eyes for dinner, will raise Don's pulse like nothing else. Along the way, Don details his family-oriented home life, the ups and downs of a legendary career, and the secretive workings of a Marvel movie set.

"World of Dance" judge Derek Hough joins Bear on a whirlwind adventure across the mountains of Bulgaria. Dropped amidst snow-capped peaks, Derek and Bear must ascend a jagged mountain ridge, make a steep rappel with Derek's cell phone as their only safety, and swim a freezing lake to reach their destination. But a surprise, death-defying final challenge will test Derek like nothing before. Along the way, Derek reveals his struggles with being bullied as a child, his devotion to his craft, and teaches Bear some much-needed dance moves.

Dropped into a vast labyrinth of limestone rock formations, the duo must rappel from a towering arch, cross a raging river and descend into a dark cave to survive their journey. As they dodge a colony of bats and face-off against a snake that Bear eyes for dinner, Scott details growing up with his famous father, his love of the outdoors, and his drive to carve his own path in Hollywood.

Tennis great Roger Federer joins Bear on a grand slam journey through the Swiss Alps. After meeting up amidst stunning snow-capped peaks, Bear and Roger descend a frozen waterfall and use tennis rackets as snowshoes to cross a frozen lake. After a quick snack of fish eyeballs, the pair get creative with a tennis ball to ascend a steep cliff that is their only way home. Along the way, Roger discusses the hard work it takes to achieve victory, his amusing experiences raising two sets of twins, and takes on the challenge when Bear invites him to a hilarious match of ping pong.

Dropped amidst snow-capped mountains, Uzo and Bear move quickly as a storm sets in, sending hail, lightning and flash floods their way. Along the way they come face-to-face with a poisonous viper, get creative to secure a dinner of field mice, and use a crossbow to zip-line across a 250 ft. drop. Despite the elements, Uzo shines as she recounts her long road to fame, her family's emigration from Nigeria, and her pride in representing the American dream.