The Call of the Wild begins with an epigraph of a John M. O'Hara poem that speaks of ancient, "ferine," and "nomadic" yearnings, or "old [wild and wandering] longings" leaping forward, chafing against "customs chains," and finally awakening into life from a "brumal sleep," or wintery hibernation.
The poem describes nature's call as a kind of awakening. The ancient longings to roam wild and free are dormant, or sleeping, but when called, they spring to life violently. This awakening foreshadows Buck's own transformation from domesticated dog to wild wolf.
The narrator introduces Buck, the proud and prized pet of Judge Miller. Buck does "not read the newspapers," so has no sense of the "trouble" that might be "brewing" around him as he cavorts around the Judge's sprawling and "sun-kissed" estate in Santa Clara, or the Southland. The "trouble" "brewing" unbeknownst to Buck is the 1879 Klondike gold rush, which has created a great demand for and high price on strong dogs, like Buck.
Buck's ignorance of world events highlights the insular quality of his life. In Santa Clara, Buck is protected and sheltered from the threats of the outside world, highlighting his domesticated status. Under the Judge's care, he enjoys the luxury of being unaware of the external factors that might harm his existence.
No other dogs equal Buck's stature as the reigning king of Judge Miller's estate. Since his birth, Buck has ruled over this land, living a comfortable and carefree life that consists of sitting by the Judge's fireside and accompanying his grandchildren on playful hunting trips, or "wild adventures" to the edges of the estate.
Through Buck's aristocratic view of the world London portrays Buck as a princely pet, whose protection of the Judge's family is merely ceremonial. Buck has no real occupation, but is content to live life comfortably as an ornamental figurehead.
Buck's world changes when Manuel, a gardener at the estate with a liking for "Chinese lottery," kidnaps Buck to pay off his gambling debts and support his wife and several children. Buck, unaware of Manuel's plan, naively accompanies him to the flag station, where an unnamed dog trader ties a rope tightly around Buck's neck. Driven by pain, anger, and humiliation, Buck attacks the man, but struggles against the rope's grip. Buck, subdued, is thrown into a crate, unconscious.
That Manuel is able to trick Buck spotlights Buck's blind trust in man. Once roped, Buck senses that his freedom is threatened and reacts fiercely. However, man's authority overpowers his own sense of mastery as Buck is quickly subdued by the rope and crate. Buck's captivity indicates that his destiny is no longer his own, but in the hands of the men who bind him.
Buck gains consciousness and realizes, from previous trips he has taken with the Judge, that he is on a train. The dog trader approaches Buck, but he bites the man's hand, lacerating it. The man chokes Buck, throwing him back into a cage-like crate. Buck seethes and starves in his crate for two days and nights as the dog trader and other vagabonds taunt and harass him. He vows never to be tied down against his will again.
Now caged, Buck realizes that his freedom has been compromised. His wild instincts awaken in the face of his captivity, so Buck reacts to this affront by lashing out savagely against his captors. That Buck vows never to be roped again underlines his innate unwillingness to bend under the mastery of others (though he has much to learn in the gaining of such mastery over himself).
In Seattle, four men unload Buck's crate. A man in a red sweater breaks it open with a hatchet. Buck launches out of the crate, leaping towards the man. He's stunned when the man strikes him with a club. Buck lunges again and again, but is struck down each time. Buck has never been beaten before. Dazed with pain from the club's blows, Buck is introduced to primitive law by learning to obey the law of club and the men who wield it. The "lesson" is driven home when he witnesses the death of a dog, who refuses to submit to the man in the red sweater's club.
From his beating at the hands of the man in the red sweater Buck is introduced to primitive law, or the laws of survival. The club is the mechanism by which Buck recognizes that man is a "master to be obeyed." He learns to submit to the power of the club—to overwhelming strength—out of pain and to obey the man who wields this weapon because with it he carries a lethal authority. The law of club firmly establishes man's authority over dog, even though Buck resists this tenet.
Buck watches as other dogs are bought and sold by the man in the red sweater. Buck along with a female dog, Curly, are bought by two French-Canadians, François and Perrault. Departing from Seattle, they take Buck and Curly to the Northland on a ship called the Narwhal. On board, François and Perrault acquire two more dogs, Spitz and Dave. At sea, Spitz steals some of Buck's food, but François whips Spitz before Buck can retaliate, thereby rising in Buck's esteem. Finally the small band of men and dogs arrives at their final destination, Dyea Beach in Alaska, where Buck steps onto something cold he's never encountered before: snow.
As Buck changes hands and moves northward, he ceases to be a pet and is now more of a commodity. He is bought and sold like every other dog he sees passing through the man in the red sweater's hands. Spitz's attempt to steal Buck's food establishes their rivalry. Spitz' success in taking the food (before François intervenes) demonstrates Spitz's mastery over Buck. Meanwhile, François's punishment of Spitz underlines man's authority as a master of canines, but also shows that François is a fair master, who exercises his power justly. Buck's first encounter with snow signals that his life is about to change greatly in the cold Northland.