In 1899, Nikki and his kind master, Andre Dupas (Jean Coutu), are traveling via canoe through the Canadian Rockies. When Nikki encounters Neewa, a black bear cub whose mother was killed by a grizzly bear named Makoos, Andre ties the two animals together, plops them in the canoe, and heads for the rapids. When the two animals become separated from Andre, the unlikely pair must learn to survive in the wilderness. When they reach land, they are forced to overcome the instinct that makes them natural enemies and join together in a search for food and shelter. Despite many fights, they eventually become friends and remain together even after their leash breaks.
With the coming of winter Neewa goes into hibernation and Nikki wanders off alone. He steals the bait from traps until he is captured by a vicious trapper named Jacques Lebeau (Émile Genest) and his reluctant Indian companion, Makoki (Uriel Luft). After watching the now full-grown dog kill a wolf in spite of the trap, Lebeau decides to train Nikki as a fighting dog although pit-fighting is illegal. When André, the new factor, challenges Lebeau for breaking the law, he is pushed into the pit with the brutalized killer dog. Nikki recognizes his old master, however, and joins André in fighting Lebeau, who is accidentally killed with his own knife. Later, while on a trip to André's trap line, Nikki spots his old friend, Neewa, but the dog realizes that the full-grown bear is happier roaming the wilds, and he chooses to remain by André's side.
