The last chapter explains how the 2010s became another lost decade in the fight against climate change – as the move to natural gas delayed a transition to more renewable sources of energy.
Engineer Tony Ingraffea, in the 1980s, helped develop a new technique for extracting gas and oil from shale rock, which ultimately became known as 'Fracking'. It was to unleash vast new reserves of fossil fuels and was promoted as a cleaner energy source. But Ingraffea explains how he later came to regret his work when he realized that gas could be even worse for climate change than coal and oil.
Dar-Lon Chang, a former ExxonMobil engineer, speaks for the first time on camera alleging that as the company increased its natural gas operations, it was not sufficiently monitoring methane leaks that were contributing to climate change. Now, after a year of unprecedented wildfires, drought and other climate-related disasters, multiple lawsuits are being brought in US courts in efforts to hold Big Oil legally accountable for the climate crisis.

One extraordinary family of fish has achieved the ultimate form of gender equality. When it comes to breeding, seahorses do it like no other animal on the planet. Their fierce females refuse to be left holding the baby. So it's the males that carry their brood. In this episode we explore the world of mating seahorses which are the only animals in the world that have a major gender role reversal.

In the last episode, despite disturbing revelations of wrongdoing at Three Mile Island before and after the accident, the utility fights to bring the plant back online. Its Unit 1 had its license temporarily suspended following the incident at Unit 2. Although the citizens of the three counties surrounding the site voted by an overwhelming margin to retire Unit 1 permanently in a non-binding resolution in 1982, it was permitted to resume operations in 1985 following a 4–1 vote by the Nuclear Regulatory Commission.
In 2017, it was announced that operations would cease by 2019 due to financial pressure from cheap natural gas, unless lawmakers stepped in to keep it open. Unit 1 shut down on September 20, 2019.
Billed as the worst nuclear incident in U.S. history, what’s particularly scary here is how close Three Mile Island incident came to becoming a national disaster. Without giving away the whole story, cost-cutting 'solutions' almost cause a catastrophic disaster.

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.

Over the past year, Chris Hemsworth have been exploring the science of living longer, doing everything he can to hold back time. But whatever he does, sooner or later, aging and death will win. Now Chris is facing his most extreme and emotional challenge: three days in a retirement village while wearing an aging suit that turns the simplest activity into a Herculean task. He'll be carrying an extra 30 pounds around and shoes that will make him unbalanced, apart from glasses to see improperly and acoustic earmuffs. Later on, Chris is going to do a death-bed meditation. He’s testing the theory that the best way to combat aging and fear of mortality might not be to fight it but accept it,

They have the raw talent, but can they handle the pressure? Now Yuki Tsunoda and Esteban Ocon must sink or swim in the rough waters of Formula 1. Yuki Tsunoda had to move from Tokyo to Milton Keynes and F1 cars are proving a bit more difficult to wield than the F2 machine in which he won races. Esteban Ocon is part of the all-French attack (from Enstone) in the shape of Alpine, soaking up the pressure to win the Hungarian GP.