In the distant future at Brittanicus Base, senior control technician Jan Garrett and her staff struggle to control an ioniser they are using to slow the progress of glaciers rolling over Great Britain. Leader Clent is convinced they can avert a new Ice Age, but the group knows they are only a few hours away from being forced to abandon the base. Tensions rise when Penley, a maverick scientist who has defected from the team, is mentioned. The remaining senior scientist, Arden, is on the glacier searching for archaeological finds, where he discovers an armoured man within a block of ice. Arden and his colleagues dig the ice man from the glacier. Two scavengers observe their actions: the anti-technology Storr and Penley, who live in the tundra. When one of Arden’s team is killed in an avalanche, the other two return to base with the ice man. Storr too is injured in the avalanche.