At the edge of camp, a muskox wanders the grounds. Far from civilization, the large animal is unfazed by the presence of humans nearby.

Steve and a team of experts ascend a mountain that no human has climbed before. As they make their way up over falling rocks and through snow, they’re also faced with three steep rock pinnacles before reaching the summit.

Expedition continues in Greenland as Steve aims to summit a steep mountain. Once the group begins their vertical climb to reach the top, there will be no sleep until they’ve worked their way back down.

Follow Steve Backshall as he tries to summit a remote and unclimbed mountain in Greenland’s Stauning Alps. After facing quicksand, a river and a glacier to reach basecamp, the climb gives Steve a unique insight into a fast-changing environment.

The Stauning Alps, at the very edge of Greenland's ice sheet, are home to countless glaciers. It’s the frontline of a global catastrophe. Fifty years ago, much of this valley was covered by a glacier, but it’s receding rapidly. Steve and the Expedition crew see first-hand climate change's massive impact on Greenland's glaciers.

Steve joins Archaeologist Guillermo de Anda as they venture into a cave where they witness the handprints of ancient Maya. It’s believed that these cave systems were sometimes used for ritual sacrifices to the gods.

Steve dives with cave expert Bernadette Carrion as they explore the Yucatan Peninsula, 200 miles across separating the Gulf of Mexico and the Caribbean. It’s almost completely flat and doesn’t appear to be extraordinarily interesting, but unbelievably, this area here could well be the ripest place on the planet for exploration.

As everyone gets ready for an exploration of an unmapped cave, expert diver Robbie Schmittner prepares a guide line for them to use. This line will help Steve and the crew make their way in and out of the water and will also serve as a guide for future explorers.

Steve observes a tarantula hawk wasp as it attacks a Mexican red-rump tarantula. After stunning the tarantula, the wasp brings it back to her burrow as a meal for her young.

Return to Mexico, where Steve Backshall explores a honeycomb of subterranean Mexican caves that the ancient Maya believed were a portal to a terrifying underworld. In a dark and flooded cave, Steve finds incredible never-before-seen artifacts.

Aldo assists the team in rigging a frame to lower Steve into a cave. As he and the other divers prepare for their descent, Steve expresses his fears about heading into the unknown and what is essentially an untouched mausoleum.

With an early start to the day, Aldo, Robbie and Steve prepare for the upcoming cave dive over coffee as Robbie goes over his instructions for the exploration. He reminds Steve of an important rule of cave diving, advising him to stay calm and avoid panicking should emergency situations arise.

During autumn every year, these long-lived Himalayan birds leave their summer nesting grounds on the Tibetan Plateau and migrate south. About 10 percent of the global population spends their winter in Bhutan’s Phobjikha Valley. Steve Backshall explains how the people there both protect and revere them.

Steve partakes in a Buddhist tradition and toasts the spirits of the river before beginning his expedition in Bhutan.

Adventure kayaker Sal Montgomery is tasked with checking out the conditions of the river and assessing the risk to crew before film commences.

Expedition cameraman James Covington runs the Chamkachu River and tries to get into all the places that other cameras can’t get to. He discusses the challenges he has faced while on Expedition and how he overcame these.

Fighting some of the most intense rapids yet, the team comes across a large drop during their journey. James Bebbington analyzes the drop by land to decide whether or not they should move forward by kayak or will need to proceed by foot to find safer waters.

Steve is joined by whitewater kayakers Darren Clarkson-King, Sal Montgomery, James Bebbington and Chencho Drukpa, to help ensure a safe passage through Bhutan’s intense rapids. Before beginning their expedition, they survey their route by land to get a better sense of what they might encounter along their journey, including dangerous “stoppers" which can pull kayakers underwater.

Join Steve Backshall in the foothills of the Himalaya, where he plans to kayak the last unrun river in Bhutan, which runs through the country’s steepest gorge. Before his attempt, Steve seeks blessing from a local Buddhist monastery.

Local people believe these mountains are sacred and revere them as the birthplace of their ancestors. The local elders give the team their blessing to enter this hidden world. Steve is joined by Indonesian rock art expert Dr. Pindi Setiawan who has spent his life exploring these cliffs and they discover something extraordinary.