Distraught, confused, and half-wild with fear, Sarah Carter emerges alone from the Appalachian cave system where she encountered unspeakable terrors. Unable to plausibly explain to the authorities what happened - or why she's covered in her friends' blood - Sarah is forced back to the subterranean depths to help locate her five missing companions. As the rescue party drives deeper into uncharted caverns, nightmarish visions of the recent past begin to haunt Sarah and she starts to realize the full horror and futility of the mission. Subjected to the suspicion and mistrust of the group and confronted once more by the inbred, feral and savagely ruthless Crawlers, Sarah must draw on all her inner reserves of strength and courage in a desperate final struggle for deliverance and redemption.

It has taken 4.6 billion years for the Earth to evolve from a barren rock into the world we know today. And now the remarkable planet is facing a new challenge: humankind. The question is, how will it survive?

Earths oceans help make our planet different from every other planet in the solar system. As far as we know, no other place is the right temp for liquid water, the most essential ingredient for life to exist and oceans are the primary stabilizing force.

Join Dr. Iain Stewart as he investigates ice crevasse's, uses satellites to discover hidden worlds, looks into ice shaping the earth's topography and shows you ice is melting so fast that this world is likely to change.