Beneath the icy surface, survivors of Colony Seven struggle as food supplies dwindle and temperatures continue to drop. Plagued by illness and internal conflict, the colonists suspect the worst when they mysteriously lose contact with Colony Five – the only other known settlement. Sam, a strong-willed mechanic with a tragic past, joins a team headed up by Briggs on a dangerous expedition to find out what happened. After a hellish trek, they discover a threat much worse than imagined, and now Colony Seven must win a savage battle to preserve the last of humanity.