A team of scientists and explorers probe high altitude caves in the Tibetan Himalayas. Along the way they discover evidence of ritual burials, thousands of years old: skeletons, mummies, and evidence of practices designed to ward off ancient vampires and even zombies.
Take a risky dive into an underwater cave in Mexico to uncover the 13,000-year old skeleton of a prehistoric teenager. Forensic clues reveal intimate details of her life and death, and how her people first ventured into North America.
Investigate the problems facing a unique population of polar bears due to climate change. At the heart is an extraordinary event: the annual gathering of up to 80 polar bears on Barter Island in the Arctic Ocean each September.