Forced underground by the next ice-age, the inhabitants of Colony 7 struggle to survive below the world's frozen surface. When they mysteriously lose contact with the only other known settlement, Briggs (Laurence Fishburne) decides to lead a dangerous mission onto the frozen wasteland determined to discover their fate.

When he and his team reach their destination, they discover a threat much worse than nature and must battle to save themselves and protect their fellow colonists in what might be humanity's last stand.