Imagine being so scared of trees that you can’t even look at one, or take your son to the park. Well, Maricela has a phobia of trees that has blighted her entire life. She has no idea how it started, but she wants it to end right now - in the middle of the Mexican jungle, with Bear Grylls pushing her to confront the trees that she actually believes can kill her. Meanwhile, Mike flinches every time he sees or hears an insect flying towards him. Together, they’re about to face their fears head on.

Bear Grylls meets two men who spend their lives avoiding confined spaces – and takes them deep into the most frightening caves he can find. Mark almost died when he was buried alive by sand as a teenager. Meanwhile, Mike was accidentally imprisoned in a fairground ride dangling almost 20 metres off the ground. He now fears being trapped so much that he can’t even hug his wife. Bear has a plan to help them face, and hopefully overcome, their worst fears. He’s heading out to one of the First World War’s most treacherous front lines, where the landscape is still punctured with trenches, caves and tunnels. But Bear will need to win Mike and Mark’s trust as he takes them deep underground.

Bear is heading sky high, and he's not stopping until he's made Joe and Claire confront the fears that are ruining their lives. Joe is so scared of heights that he can’t even change a light bulb or stand near a balcony. Meanwhile, Claire suffers with a fear of falling that stops her from enjoying adventurous activities with her daughter. Bear puts his reputation on the line as he pushesthem further than ever before, exposing them to the jaw-dropping heights of the Dolomites mountain range in Italy. By believing in Bear and pushing themselves way out of their comfort zones, they’ll find themselves taking on a truly spectacular challenge.

Bear Grylls gets down and dirty with two men who are terrified of rats and spiders. Back home, British carpenter Joe keeps his fear of creepy-crawlies a complete secret to avoid being ridiculed by his workmates, who come across spiders every day. Meanwhile, Neo grew up in South Africa where he developed an irrational fear of rats that’s stayed with him all the way into adulthood. Now, Joe and Neo are going to come face-to-face with their worst nightmares as Bear pushes them deep into the Mexican jungle, with its super-sized rodents and arachnids.

Bear Grylls is in for a tough ride as he tries to help two men overcome their fear of germs and strange foods. Toby, 28, is terrified of coming into contact with blood or dirt, after suffering with Obsessive Compulsive Disorder since he was a teenager. But he’s always wanted to be an adventurer, so he has signed up to confront his issues head-on. Jim, 35, is frightened of trying new foods and has stuck to the same limited diet since he was a child. Now, with two children of his own, he’s concerned that they’ll copy his habits and he’ll pass his food fears on to them. So he’s taken the radical decision to go away with Bear Grylls - a man with a reputation for eating absolutely anything he finds while surviving in the wild. Jim and Toby are both desperately hoping that Bear can help them stamp out their fears for good.

New Yorker Ray and Ugur from Holland are both terrified of water after suffering major trauma in their lives. Bear takes them to face their fears on a journey through fast-flowing jungle waterways in Southern Mexico. Ray, 60, lost his son, Marc, in a tragic accident in a swimming pool. It had been Marc’s dream to join the Navy Seals, but he drowned aged just 17, leaving Ray haunted by images of his son dying underwater. Ugur, 37, was in Thailand when the Asian tsunami hit – and he’s avoided water ever since. Can Bear take these two proud men and force them to overcome their fears by taking on some of the world’s deepest canyons and highest waterfalls? It’s going to be an emotional journey.