Just about every solid, liquid, or gas in the world as we know it begins with reactions between individual atoms and molecules. Host David Pogue dives into the transformative world of chemical reactions, from the complex formula that produces cement to the single reaction that’s allowed farmers to feed a global population by the billions.

Fueled by a ruthless and maniacal ambition to conquer Central Japan, Nobunaga has destroyed many enemies who have underestimated him. His vicious military campaigns to weaken the powerful Buddhist institutions have turned large swathes of the population against him. As Nobunaga's cruelty intensifies, some generals begin to question his command, leading to a betrayal that alters the political landscape forever.

Episode 4 rounds everything out while simultaneously focusing on his career and the next steps. After a performance tribute to Jamal, Ed and Cherry get good news and reflect on a turbulent year.

As tides rise and fall twice a day, vast amounts of water swirl around the earth. This is a huge energy source that's currently largely untapped. An estimated 3000 gigawatts are available to be harvested globally, enough to power a third of the earth's homes. Yet compared to wind and solar, the technology needed to harness tidal power is still in its infancy. The power of the ocean’s tides is the last great untapped energy source on Earth. From sub-sea kites to floating platforms, teams of engineers are racing to perfect the technology to harness the vast flows of water.

A new force threatens our perfect planet. In the past, five mass extinction events were caused by cataclysmic volcanic eruptions. It was not the lava or ash that wiped out life, but an invisible gas released by volcanoes: carbon dioxide. Almost every part of modern life depends on energy created by burning fossil fuels, and this produces CO2 in huge amounts. Humans are changing our planet so rapidly, it’s affecting earth’s life support systems: our weather, our oceans and the living world. The greatest change to be made is in how we create energy, and the planet is brimming with natural power that can help us do just that. It’s these forces of nature - the wind, the sun, waves and geothermal energy - that hold the key to our future.
Through compelling animal-led stories and expert interviews, we discover how CO2 is destabilising our planet. We meet rescued orphaned elephants in Kenya, victims of ever worsening droughts, and join ocean patrols off the coast of Gabon fighting to save endangered sharks. In the Amazon, we witness wildlife teams saving animals in the shrinking forests, and in San Diego we enter a cryogenic zoo preserving the DNA of endangered species before they become extinct.

Ma Anand Sheela emerges as a provocative spokeswoman. The Rajneesh control Antelope city council and they establish a police force in the city. Bhagwan tells Sheela it is time to control Wasco County. As Election Day approaches, the Rajneeshees recruit thousands of homeless people to fortify their ranks.