The animals of the north face worsening weather in autumn and the first stirrings of winter. Grey seals and reindeer turn their attention to mating, hormones run wild as males compete and young animals venture away from their parents for the first time. In Iceland, the cliff arctic fox family is thriving, but it’s a different story for the foxes denning at the shoreline. Only one of the cubs has survived, now abandoned by her parents, she must fend for herself. On the Monach Isles, 35,000 grey seals arrive for the annual breeding season. A pup faces danger on the beach, getting lost and swept up into a fight between two raging bulls. As winter arrives, the reindeer herd in Norway must migrate to their grazing grounds in the mountains but this involves a perilous two-mile swim across open water.