Chapter 1. Into the Primitive
Buck is a happy, contented dog who lives on Judge Miller's estate in California in the late 19th century. He has a dignified, gentle nature and has always been treated like a king. Buck's life is turned upside down when he is kidnapped by Manual, one of the gardeners, and sold to men rushing to the Alaskan wilderness in search of gold. After two days chained down on a train without food, Buck arrives in Seattle in a state of bewildered rage. Determined to escape, Buck is faced by "the man with the red sweater" who repeatedly repels Buck's attacks by hitting him savagely with a club. Learning that he cannot win against the club is first lesson about the harsh realities of his new world. Though he behaves obediently, his inner spirit remains determined.
Buck is sold to Perrault and Francois, two gold seekers who recognize Buck's potential. Buck boards a ship with the other dogs and his new masters, and they set sail for the Alaskan wilderness. When the ship finally docks, Buck is surprised by the white, mushy ground. It is his first encounter with snow.
Chapter 2. The Law of Club and Fang
On the first day of his life in the north Buck sees the other sled dogs viciously attack and kill Curly, a new dog who had arrived with Buck. Seeing this vicious and unprovoked attack leads Buck to the realization that his new cruel, "nightmarish" surroundings require him to look out for himself constantly in order to survive.
Buck is harnessed for the first time and ordered to pull the sled with the other dogs. At first, he is surprised and at first does not understand what is expected of him, but he is a fast learner and quickly comes to understand the commands and expectations of his masters. Three more dogs are added to the team: Billee, a friendly and good-natured husky; Joe, Billee's nasty and uncaring brother; and Sol-leks, a one-eyed, angry husky.
By watching the other dogs, Buck learns to dig a hole into the snow and sleep in it in order to keep warm throughout the night.
As the team travels miles and miles through the harsh Alaskan wilderness each day, Buck begins to change. His morals begin to change: he steals food in order to get enough to eat. His body begins to change: his muscles become stronger and his senses become heightened. His instincts begin to change: he begins to feel a strong connection to his wild wolf ancestors of the past. Buck realizes being kidnapped by Manuel has changed his life forever.
Chapter 3. The Dominant Primordial Beast
Growing accustomed to the harsh world aroung him, Buck develops inner poise and control fueled by primitive instincts. These changes threaten Spitz, the lead sled dog, who challenges Buck at every turn, and the two begin fighting. A fight over Buck's sleeping nest is disrupted when a pack of starving huskies invades the camp, requiring that Perrault, Francois, and the sled dogs fight off the invaders to save their supplies and their lives. Despite their injuries, the team continues their journey across the treacherous Thirty Mile River.
When Dolly goes mad and chases Buck aggressively, Francois is forced to shoot her. Spitz attacks the fatigued Buck, only to be disciplined by Francois. From this point on, Buck openly challenges Spitz's leadership in an attempt to win supremacy. He incites unruliness among the dogs and undermines the team's ability to work as a cohesive unit, much to the frustration of Perrault and Francois.
After camping one night, the dogs chase a wild rabbit. Fueled by his wild instincts, Buck is determined to catch his prey. When Spitz kills the rabbit first, Buck realizes that the time has come to fight Spitz to the death. By sheer force of his ancestral instincts, Buck prevails over the more experienced Spitz. The dominant primordial beast in Buck is proud of his conquest.
Chapter 4. Who Has Won to Mastership
Buck's expectation that he will now become the lead sled dog is thwarted when Perrault chooses Sol-leks to take over Spitz's position. The outraged Buck uses his new-found determination and sheer will to resist all attempts to harness him behind Sol-leks, until finally he is placed in the lead position. Francois and Perrault are amazed by Buck's skill and control as leader, and the sled team makes it to Skaguay in record time.
The dogs' life changes quickly again when they are sold to a man in charge of delivering mail and they begin a series of rapid trips to and from Dawson. At night by the fire Buck withdraws into his imagination, dreaming of his ancestors and the cavemen of prehistoric times. Buck seems to be transforming from a domesticated dog into the wild wolf that he sees in his visions.
Although the dogs are generally well cared for, the grueling pace of the work wears them all down. Dave sickens, losing his strength and enduring pain of unknown cause. When the new master tries to remove him from the traces to spare him, Dave's pride is devastated, and he refuses to give up. The master puts him back into the team so that he can die with dignity. Dave pushes on until all of his strength is gone, when the master is forced to end his misery by shooting him.
Chapter 5. The Toil of Trace and Trail
Buck and his team are weak and completely exhausted by the time they arrive at Skaguay. After only four days of rest, they are sold once again to Hal, Charles and Mercedes, newcomers who have no experience leading a team of dogs through the arctic wilderness.
Poor planning and callousness fuel severe mistreatment of the dogs by their new owners and lead to very slow progress on the trail. The three masters constantly argue among themselves, and Mercedes angers her companions by her helpless and spoiled attitude, demanding that the dogs pull her on the sled. Weak, bruised, and half-dead, the dogs do their best but are battered and whipped when they fall. Billee and Koona die along the trail.
At the mouth of the White River, they meet John Thornton. Ignoring John's warning that melting river ice makes it unsafe to travel further, Hal urges the dogs to continue. When Buck refuses to follow, Hal beats him until John Thornton intervenes and refuses to let Hal take Buck further. Buck and John watch the team set out and then fall through the ice to their deaths.
Chapter 6. For the Love of Man
During days and weeks with the kind John Thornton and his dogs Skeet and Nig, Buck rests are restores his strength. A bond of mutual unconditional love develops between Buck and John. In his gratitude and affection, Buck sticks close to John's side and they exchange playful expressions of devotion and respect. But even as he develops a deep attachment to John Thornton, Buck continues to feel a pull to the wildness of his ancestors. Lying by John's fire, he dreams of the forest and of the life of the wild wolves.
Back in the mining town, Buck demonstrates his deep love for John three different times. First, Buck attacks a man who attempts to fight John in a bar. Going straight for the man's throat, Buck immediately gains a reputation for being loyal, ferocious, and protective. Second, Buck rescues John from the rapid water of the Forty Mile Creek, battling the cold and the current repeatedly until he succeeds in saving John. Finally, Buck wins a bet for John Thornton that makes him a very rich man. John wagers that Buck will be able to pull one thousand pounds for one hundred yards. To everyone's astonishment, Buck is able to accomplish the incredible feat, and John Thornton wins sixteen hundred dollars.
Chapter 7. The Sounding of the Call
John Thornton uses his winnings to finance a journey to the east to find a fabled gold mine called the Lost Cabin. After months of travel into the wilderness, they find a field of gold and settle down to mine it.
While John amasses gold, Buck becomes restless, ranging further and further into the wilderness at night. One night he begins to follow a wild timber wolf off into the forest only to be pulled back by his love and loyalty to John. His wildness and his loyalty warring within him, Buck spends increasing amounts of time in the woods, letting his inner beast emerge, honing his instincts, speed, and strength to prey on other wild animals.
After an especially long foray tracking and killing a large moose, Buck feels that something important has changed in the forest. He returns to the camp to finds that Thornton and the team have been viciously killed by the Yeehats. Enraged, Buck attacks the tribe and kills many of them in revenge. In grief he returns to the forest, with no further ties to civilization. He encounters his "wild wolf brother," the timber wolf. After establishing his dominance, Buck is accepted into the pack and fully embraces the call of the wild.
In the years to come, the Yeehats pass down a legend of a "Ghost Dog" and an "Evil Spirit" that continues to haunt them. As the story goes, a great and powerful wolf visits the valley every summer and stops to howl mournfully by the yellow stream. The great wolf can sometimes be seen leading a wild pack, singing the song of his ancestors.