Covering one tenth of all species on the planet, Freshwater is a rich, diverse habitat filled with never-ending surprises. The fourth episode is set beneath the Yucatan Peninsula and spanning diverse locations like the rainforests of Costa Rica and the Kalahari Desert and presents a vivid exploration of how freshwater shapes life on Earth. The narrative journeys through the unique breeding rituals of gliding tree frogs in Costa Rica, the strategic hunting methods of mugger crocodiles in Sri Lanka, and the astonishing adaptations of wildlife in the Okavango Delta. It highlights the critical role of freshwater in supporting diverse ecosystems, from the teeming fish species in Lake Malawi to the perilous journey of gobies in Bioko.
The episode also addresses human impact, showcasing the extensive irrigation system in Pakistan and its unintended consequences on local wildlife, like the endangered Indus river dolphin. This captivating chapter not only showcases nature's marvels but also underscores the delicate balance between human needs and wildlife conservation.

This featured episode of the documentary series takes viewers on a captivating journey around the world, showcasing the astonishing ways in which animals adapt to living alongside humans. In Sauraha, Nepal, a rhino navigates through human-inhabited areas in search of food. In Bali, long-tailed macaques have learned to trade stolen items for food, demonstrating their intelligence and adaptability. The bustling streets of New York City are home to pavement ants that thrive on human leftovers, while in India, revered cobras coexist with humans in a unique cultural relationship.
Melbourne, Australia, features nocturnal frogmouths benefiting from urban lighting for hunting, and Lake Tahoe in North America sees black bears adapting to easy food sources in human settlements. The documentary also delves into the challenges faced by wildlife due to human expansion and climate change. It highlights the plight of African elephants in Kenya conflicting with farmers, the impact of overfishing on humpback whales in Vancouver Island, and the dramatic increase of desert locusts in northeastern Africa due to climate-induced conditions.
The episode concludes by emphasizing the importance of reimagining our relationship with nature. It suggests a shift towards plant-based diets to reduce agricultural land use and the potential of vertical farming technologies, offering hope and solutions for a sustainable coexistence with wildlife.

Werner Boote presents an up-close and personal view of the controversial and fascinating material that has found its way into every facet of our daily lives: plastic. He takes us on a journey around the globe, showing that plastics have become a threat for both environment and human health.

Adam Rutherford meets a new creature created by American scientists, the spider-goat. It is part goat, part spider, and its milk can be used to create artificial spider's web. It is part of a new field of research, synthetic biology, with a radical aim: to break down nature into spare parts so that we can rebuild it however we please. This technology is already being used to make bio-diesel to power cars. Other researchers are looking at how we might, one day, control human emotions by sending 'biological machines' into our brains.

The film explores the revolutionary gene-editing tech now giving humankind the freedom to redraw the blueprint of biological life itself. We investigate not only the tremendous potential the technology holds, whether in the fight to eliminate diseases or in transforming agriculture to adapt to unprecedented climate extremes, but also probe the inherent risks involved and the potential for widespread abuse, dangers that could take our future down a very dark, dystopian path.

Playing with Nuclear Fire' - In March 2011, the Tohoku earthquake in Japan created a tsunami that killed some 16,000 people and crippled the Fukushima Daiichi nuclear power plant. In the aftermath, the government and TEPCO, the plant's operator, withheld information about the extent of the damage. Three years later, citizens and the international community are left wondering if Japan really does have the situation under control, as the government is insisting, or if the danger is far greater than anyone is willing to admit. 'No Man Left Behind' - It's estimated that over a quarter million vets from recent wars have sought treatment for PTSD. Despite these statistics, veterans often face an uphill battle to get treatment, receiving inadequate attention and, most dangerously, overprescribed narcotics and other pharmaceuticals. Ryan Duffy meets veterans struggling with mental illness and addiction.