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 such as beech trees in Antarctica and 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. Find out what caused such dramatic changes at the ends of the Earth, and what the past can reveal about our planet’s climate today and in the future.

Watch it tonight at 8pm on WGBH 2.