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.