There was a bitter hatred between Buck and Spitz, but Buck made it a point to avoid a confrontation. One blustery, cold night, as they were getting ready to turn in, Buck left his sleeping hole to get his food. When he returned, he found that Spitz had crawled into his pit. This was too much to tolerate and to everyone's surprise, he angrily sprang at him. François was also surprised but knew the cause. He encouraged Buck to "give it to him". Just then the unexpected happened.
A group of starving huskies that had picked up the scent of the camp had crept in when Spitz and Buck were fighting. Crazed by the smell of food, they fought back when the men sprang among them with clubs. The team dogs burst forth from their sleeping holes and were astonished to see the invaders. Buck had never seen such skinny, sickly looking dogs. He did not have much time to be astonished by the sight as he was attacked by three of the invading huskies. In a moment his head and shoulders were slashed.
The camp was in turmoil as everyone was fighting for survival. When the attackers found the food in the tents, their attention was thoroughly consumed and there seemed to be a moment of calmness. Suddenly, Buck felt teeth sink into his own throat. He was surprised when he realized that it was Spitz treacherously attacking him from the side. He knew that if he were knocked off his feet there would be no hope for him, so he just braced his legs and stood firm under Spitz' attack. Spitz' maneuvers became secondary when the invading huskies came back for a second round in their eagerness to squelch their hunger.
Perrault and Francois tried to intervene but they were no match against these brutes. Finally, they were able to chase them off but not before a lot of damage resulted. The huskies had chewed up the tent lashings and canvass coverings, Perrault's moccasins, chunks of leather traces, and even the length of Francois' lashing whip. Francois was worried that the wild huskies might have infected the dogs with rabies.
There were 400 miles of trail left to Dawson and it was the hardest part of the trail. The wounds that the dogs had suffered were stiff and they struggled painfully. The Three-Mile River was not fully frozen and it took six days of exhausting toil to cross it. Every foot of it was risk to dog and man. The weather dropped to 50 below but Perrault forged on. Every time the ice broke and Perrault fell through, a fire had to be lit and clothes dried
Another time, Spitz fell, dragging the whole team with him up to Buck's spot. Buck strained backward with all his strength. His forepaws were sliding on the slippery edge; the ice was quivering and snapping all around him. Dave backed him up, straining backwards also. No escape seemed possible except to head up the difficult path on the cliff. Perrault and Francois scaled it miraculously, and lashing all the available ropes and harnesses, hoisted the dogs up.
To make up for lost time, Perrault pushed them even harder and they covered about one hundred twenty miles in three days. Buck's feet were not hard and compact like the Huskies' and this frenzied pace hurt his feet. He limped in agony all day long and lay down like dead once the camp was reached. François brought him his food and rubbed his feet each night for half an hour. He even gave up his moccasins to make shoes for Buck. Later his feet hardened and he no longer needed the footgear.
At Pelly, Dolly went mad from rabies and sprang at Buck without a reason. Buck ran away realizing that there was something wrong. He had never seen madness but he knew that he must fear it. Dolly followed very close behind. No matter how hard he ran, he could not shake her off. Not knowing what else to do, Buck doubled back to camp. Fortunately Francois was there and saved him by killing Dolly.
Buck was exhausted and staggered over to the sled, panting for breath. Now Spitz saw his opportunity, and provoked him into fighting. Francois saw what was happening and dealt Spitz the worst whipping ever. "Someday that devil will kill Buck" to which Perrault replied "that Buck is two devils"
The clash for leadership was inevitable and Spitz saw him as a rival and threat. Buck openly threatened him and he deliberately sheltered the erring dogs from Spitz' punishments. Because of this mutiny, a general unrest among the team sprang up. Only Dave and Sol-leks remained unaffected. Things weren't going right as there was continuous bickering and jangling. Buck was always at the bottom of the trouble. Françoise knew about the life and death struggle between the two, and was worried.
They finally pulled into Dawson. There was a constant hustle and bustle and everybody was busy at work. All the dogs that they saw there were at work pulling loads up and down the street and never seemed to sit and rest. Even at night, they were awake as one could hear their wolfish howls. Buck, to his own surprise, found himself chiming in with a wolf-like call.
After only seven days in Dawson, Perrault was told to carry another dispatch to the Yukon trail towards Dyea and the backwaters. The dogs were raring to go, having recouped with a week's rest. The weather favored a fast journey, as the trail was now compact. They traveled light as the police had arranged rest spots in three or four places along the trail providing food for men and beasts.
On the first day they covered sixty miles and on the second day they neared Pelly. This record breaking travel time was blemished with tribulations for Francois. Buck's behavior toward Spitz had undermined his authority as a leader and had broken the team's unity. There were constant fights and arguments among the team-mates and Spitz was unable to restore order. This unending squabbling irritated Dave and Sol-leks but no one knew what to do. François swore strange oaths and tore his hair and stamped his feet in the snow while his lash kept swinging in the air. He backed up Spitz with his whip but Buck backed up the others. François knew that he was the cause of all trouble but Buck was too clever to be caught red handed. Toil was his delight and he worked faithfully in harness. The other delight was to slyly stir up some quarrel among the mates and tangle the traces.
At Tahkeena, Dub noticed a snowshoe rabbit and soon the whole team was in full pursuit. Fifty other huskies of the North West Police also joined the chase. The rabbit ran lightly up the creek across the snow bed and held a steady pace. The dogs followed in close pursuit. Buck led a pack of sixty dogs, but could not gain on the rabbit. The rabbit stayed constantly ahead of them.
In contrast, Spitz cunningly cut through the island diagonally, and jumped right in the path of the flying rabbit, preempting his mates. The rabbit shrieked as his teeth bit into its throat, a cry of life in the grip of death. The pack joined in a chorus of delight but Buck did not consider this to be the end of the chase. He kept going and headed straight for Spitz. His charge made them both fall and they rolled over and over in the powdery snow. Spitz quickly jumped to his feet and slashed Buck. Then Buck knew that the time had come. It was the fight to finish. They circled about, watching for advantage, ears laid back, snarling, Spitz was a cold and calculating fighter.
Buck could not penetrate his guard and the two opponents kept snarling at each other. Spitz kept rushing and staggering Buck off balance but he quickly recovered. After a while of this back and forth nothingness, Buck changed his strategy. He would pretend to do one thing and quickly change his tactic. His quick shrewdness allowed him to break one of Spitz' forelegs and gain the upper hand. Spitz realized that he had no chance as he staggered and fell backwards.
Buck was the successful champion and liked the moment of victory.
London vividly describes the dangers that are constantly present in the wilderness; hunger, madness, and weather conditions. Even though Francois and Perrault are experienced travelers of this region, they are no match to the onslaught of the wild dogs who are crazed with hunger and the team has to unite on their own to combat the common enemy.
The rivalry that exists between Spitz and Buck reaches a climax and their tactics to achieve the leadership position take on human qualities. Buck's behavior exhibits shrewdness and political savvy when he sides with the weaker animals and undercuts Spitz' authority.