Return of the Ice is set in Europe, 5,000,000 years into the future. The episode focuses on three species:-
Shagrat - a descendant of the marmot that has grown in size and developed thicker fur to protect it from the cold.
Snowstalker - a descendant of the wolverine that has evolved sabre-teeth and white fur for camouflage.
Gannetwhale - a descendant of the gannet which has grown to immense size to replace the sea mammals.
The episode follows the story of a female Snowstalker teaching her cubs to hunt, the Gannetwhale's breeding season and the mass migration to the south of the Shagrats.
