Buck’s beastly nature steadily grows, although he keeps it a . He picks no , avoiding them whenever possible. Sensing a rival, Spitz never misses an opportunity to show Buck his . Many times he attempts to start a fight that must end in one of their . Buck resists his growing hatred of until one particularly difficult and cold night when Spitz tried to take over Buck’s nest. Angrily, Buck leaps at Spitz and they fight until it is broken up by one of the men.
Suddenly four or five starving invaded the camp. Buck never saw dogs so . The strange huskies attack and Buck finds himself viciously fighting for his . Just as he kills two of the huskies Spitz attacks Buck from the . Buck shakes him off and concentrates on driving off the strange dogs.
The Mile River was wide open, and it took days for them to travel thirty miles. Occasionally they broke through the , and the dogs had to be thawed by a .
Buck's begin to give him trouble, and Francois made Buck four which he used until his feet grew tough. One of the newest dogs named Dolly becomes mad and attacks Buck. Francois kills with an axe.
Everyone seems to know that the fight between and Spitz is eventually going to happen. Buck wants it. He craves it because it is in his nature. The team eventually arrives in and Buck marvels at the sight of the dogs, everywhere working. Each night the howl together, singing an ancient song.
A week later the team leaves Dawson. is carrying urgent dispatches and he is determined to set a record. They travel fast and well. One night the dogs spot a , and they chase after it. Buck and Spitz began fighting over the rabbit, and then with each other. After a few moments Buck is covered in , while Spitz is untouched. Spitz is an experienced , but Buck possesses imagination. He tricks his rival, and is able to break both . Spitz is beaten. Buck knows that this is no place for mercy. He knocks Spitz onto his back and the dogs rush in to kill him.