Chris Packham explores one of the darkest periods in Earth’s history: the worst mass extinction the planet has ever seen, when as much as 90% of all species died 252 million years ago. This extraordinary moment in Earth’s history took life to the brink, wreaking havoc and destruction on an unprecedented scale. But, somehow, life found a way to bounce back, and a new geological era ushered in the age of the dinosaurs.

Earth’s terrifying journey into the deep freeze starts with fire, not ice. 800 million years ago, long before the age of the dinosaurs, before there was even animal life, the giant supercontinent Rodinia breaks up. Earth’s vast powerful tectonic forces rip the land apart, kicking off a series of events that results in huge amounts of carbon dioxide being sucked from the atmosphere and sending global temperatures plummeting.

When Earth first formed from clouds of dust and gas 4.6 billion years ago, it was - like so many other lifeless worlds in the universe - devoid of an atmosphere, an inhospitable rock floating in the black void of space. But as the young planet is pummelled by asteroids, a period of extraordinary upheaval begins.

Today, Earth is a human world, home to eight billion people and counting. Humans now have a greater effect in shaping Earth’s surface than many natural processes. Chris Packham explores how dramatic twists in Earth’s story enabled humans to go from being part of nature to controlling it and what can be learnt from this epic tale before it’s too late.