Ka's mother is Matriarch over all the elephants in the Valley, and one day Ka will be Matriarch herself. Ra is a rhinocerous whose family has been chased from their home. On the banks of the Cold River grow the thistles and thorns Ra and his family like best, but the elephants regard this land sacred. Ra and Ka must learn to overcome their differences and work together to protect their land and food from an even greater threat.