Rival animal dynasties attempt to gain control of the kingdom, and in the midst of their struggles for power, one leader's reign reaches its tragic end.
A mother is forced to teach her young cubs important lessons about survival amid rising flood waters that pose threats to their lives and to their home.
Glenn returns to his camp after months away, knowing only that grizzly bears are in the area; Andy and Kate's apprentice wakes after his campfire goes out.
Sue travels to Deadhorse to pick up her new all-terrain vehicle; Andy and Kate help their apprentice figure out how to make a living in the wilderness.
Chip heads onto the tundra to locate his son and daughter when they are late for a hunting expedition; Sue goes looking for fresh water as a storm approaches.
A coming snowstorm threatens to crush Sue's food tent; Andy has to get his dogs into harness quickly for a supply run; Glenn follows a wolf to find caribou.
Sue switches from hunting to fishing when the caribou are scarce; Andy and Kate train their dogs to travel by canoe; Chip and Agnes hunt for seagull eggs.
Sue uses a World War II transport to move her food container to safety before the freeze; Glenn hunts to feed himself; Chip and Agnes' boat starts to sink.
A harsh drought hits the region and affects all the animals, which forces the mothers to search for a way to save their offspring from a deadly situation.