Season 1 — Episode 4
For the animals of the polar regions, time is running out in the autumn as the Arctic Ocean freezes over and the sea ice advances around Antarctica. Hordes of polar bears gather on the Arctic coast waiting for the return of the ice. Beluga whales head to an estuary to thrash their bodies against the gravel and exfoliate in a gigantic 'whale spa'. Inland, the tundra dramatically transforms from green to fiery red and musk ox fight to defend their harems.