In 2002, an immense, 200 meter-thick ice shelf, the size of Manhattan, collapsed into the ocean off the Antarctic Peninsula, shocking scientists and raising the alarming possibility that we may be heading toward an ice-free Antarctica -- last seen a million years ago. That would raise world sea levels so high that New York City would be flooded up to the level of the Statue of Liberty's shoulders. But could this really happen? Is Antarctica's surprising past a reliable guide to what may happen to our warming planet? To gather crucial evidence, NOVA follows the most ambitious scientific project launched during the International Polar Year: a state-of-the-art drilling probe known as ANDRILL. Penetrating more than a kilometer through the floating sea ice, ANDRILL recovers evidence from the seabed that reveals details of climate and fauna from a time when dinosaurs and forests once thrived in Antarctica. As the scientists grapple with the harshest conditions on earth, they discover astonishing and disturbing new clues. Once thought to be locked in a solid deep freeze for the last 15 million years, it now looks like Antarctica's ice has melted and frozen again dozens of times during that period. This breakthrough discovery carries ominous implications for coastal cities around the globe.