In a race against developers in the Rocky Mountains, paleontologists uncover a unique fossil site packed with astonishingly well-preserved bones of mammoths, mastodons, and other giant extinct beasts. The discovery opens a highly focused window on the vanished world of the Ice Age in North America.

Renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar extremes of our planet. Following a trail of strange fossils found in all the wrong places—beech trees in Antarctica, hippo-like mammals in the Arctic—Johnson uncovers the bizarre history of the poles, from miles-high ice sheets to warm polar forests teeming with life. What caused such dramatic changes at the ends of the Earth? And what can the past reveal about our planet’s climate today—and in the future?

Ranger Megan Patel loses her brother, Daniel, under mysterious circumstances. Struggling to understand how he died, she finds herself alone, venturing into the vast pine forest. However, as she follows the trail of her brother into the woods, the trees begin to change and shift around her. Soon Megan arrives in places without any recollection of how she got there. Almost as if something is pulling her deeper into the woods. Something dark and dangerous, that Megan might not be able to escape.

Five times, Earth has faced apocalyptic events that swept nearly all life from the face of the planet. What did these prehistoric creatures look like? What catastrophes caused their disappearance? And how did our distant ancestors survive and give rise to the world we know today?

Travel back 66 million years ago when a meteor struck the Earth, wiping out three-quarters of all life on the planet. What happened in those first hours? Why did some creatures survive while nearly all others perished? Using computer graphics and real-world recreations, National Geographic reveals the likely effects of the catastrophic impact that changed the world forever and examines who won, who lost, and why.