Buck, a huge and handsome dog, lives on an extensive estate in California’s Santa Clara Valley owned by the wealthy Judge Miller. Buck is four years old and is the undoubted master of Judge Miller’s place, as the locals call it. He is loved by the Miller children and grandchildren. But Buck is ignorant to the fact that there hovers a shadow over his happy life. It is 1897, and men from all over the world are traveling north for the gold rush that has hit the Klondike region of Canada, just east of Alaska. They require strong dogs to pull their sleds on the difficult journey. Buck does not realize that Manuel, a gardener on Judge Miller’s estate, is an unreliable associate. Manuel’s love of gambling in the Chinese lottery makes it difficult for him to support his wife and several children. One day, while the judge is away, Manuel takes Buck for a walk and leads him to a flag station where a stranger waits for him. Money changes hands and Buck attacks the stranger to rescue himself from them but he finds it impossible to break free. The man fights back and Buck’s strength fails. He blacks out and is thrown into the baggage car of the train.
After regaining consciousness he tries his best to rescue himself again and bites the kidnapper’s hand. He is then thrown down and choked repeatedly then locked into a cage like crate. Without food and water he stays there for the rest of the night and then he is passed from one vehicle to the other. He becomes more and more angry and decides never to let his tormentors tie a rope around his neck again. In Seattle, Buck’s crate is lifted into a small yard with high walls and a stout man signs for him. Buck understands that this new man is his next tormentor and he snarls and growls and leaps at the man with all his weight. For the first time he is beaten with a club and this hurts and stuns him. He continues trying to attack until the man beats him into submission. When Buck is finally exhausted, the man brings him water and meat and pats him on the head. Buck realizes that he should not stand a chance against a man with a club and submits himself. Buck watches other men arrive, sometimes taking other dogs away with them, and he is glad that he is not chosen. Finally the time comes for him when a French Canadian named Perrault buys him and a Newfoundland bitch named Curly. They are taken onto a ship called the Narwhal and turned over to another French Canadian named Francois. They join two other dogs, Spitz and Dave, on the journey northward. Buck realizes that the weather is continuously growing colder until finally, they arrive into a cold surface that Buck does not recognize, never having seen snow before.
Buck realizes that he has been ousted from civilization into the lap of the wild and his first day in the North is very depressing. Both the dogs and the men around him are very cruel and he is even shocked to see the pitiless dogs fight. Buck is stunned when Curly, the female dog, is attacked and killed by the brutal creatures. He understands that to survive he should avoid any kind of fight. He is then fastened with a strap by Francois and is set to carry a sleigh. He tries his best to respond to the whip of Francois and the growls of the other experienced dogs, especially Spitz who is the team’s lead dog and whom Buck feels like hating. Spitz leads them carving a path through the snow and Buck learns the art quickly and makes good progress. Later two more dogs, Billee and Joe are joined in. though brothers they are completely different in nature – Billee is extremely good-natured while Joe is bitter. Another dog, Sol-leks, an old husky and one eyed, also joins them. Gradually the team becomes big and Buck learns a lot from the company. When he does not get place to sleep he learns to dig a hole in the snow for him to be comfortable, when hungry he learns to eat fast before the disappearance of food and leaving his old morals he even learns to steal.
The sleigh dogs are even attacked by the starving wild dogs. Finally the team manages to reach the most difficult stretch – the frozen lakes and rivers where the surface is partly melted. At times they take immense risks, and many of the dogs break through the ice and almost freeze to death or drown. Dolly, one of the dogs, goes mad one morning and begins chasing Buck and finally Francois kills the mad dog. Spitz and Buck gradually becomes great rivals and an undeclared war with a fight to death situation becomes unavoidable. Realizing the situation Francois bets on Buck and Perrault on Spitz. Buck threatens Spitz’s leadership by teaming up with the weaker dogs and as the team pushes over from Dawson towards Skaguav, Bucks rebellion against Spitz keeps increasing. Finally a severe fight takes place and under the watch of the other dogs Buck finishes Spitz off. Buck tries to take the position of Spitz and when Francois gives the place to Sol-leks Buck shows his resentment. Sol-leks shows his fear against Buck and even Perrault suggests Francois to take the desirable decision. Buck takes up the job and tries to show himself even superior to
Spitz. Like a born leader he expects the others to live up to his expectations. The team progresses very well and even make a remarkable record of their journey that makes them very popular in a very short time. Perrault and Francois soon receive official orders to move somewhere else and they exit from the life of Buck. The team, under the command of a Scotsman, travels back to Dawson carrying a heavy load of mail to the gold miners in the North. With such a load, their speed becomes nat slows, and life becomes monotonous and laborious for Buck. Though he thinks about his life in California often, he is not homesick. His inherited instincts grow stronger within him and whatever he encounters in the wild seem peculiarly familiar. The men around him remind him of people of another, more primitive time. Sometimes at night he even has hallucinations that seem to come from a previous era, when men wore animal skins and lived in caves.
When, after a long journey, they arrive completely exhausted at Skaguay they are immediately ordered to deliver more mail. The dogs are replaced and Buck and his mates are sold to two men, Hal and Charles and a materialistic lady Mercedes, who have recently arrived from US. The new owners are less organized and less professional than their previous owners. Buck is not very happy with his new owners whom he finds to be very lazy and careless. Their ineffectiveness makes their progress irregular and to add to their woes they are underfed when they run out of food. With little compassion for the animals their owners keep arguing among themselves. Buck is totally worn out with starvation and fatigue. Many of his fellows, along with Billee pass away. Soon they are only five in the team fighting with starvation. It is springtime and the snow begins to melt. When they reach John Thornton’s camp, the experienced gold hunter advices them not to venture as the melting ice increases the risk of falling. But the owners ignore him and cruelly forces the dogs back into harness. When Buck refuses he is brutally whipped by Hal. Thornton, who has been watching the inhuman behavior, saves Buck from the cruel hands of his owners. The rest of the team moves on and Buck stays back in the care of Thornton. Thornton checks over his broken bones and finds that Buck is fatigued, injured and starved. From a distance Thornton and Buck watch the rest of the team crawl over the ice. Suddenly they hear a scream and they see a section of the ice give away and the whole team drop down and disappear into the dark water.
Buck slowly regains his strength and develops, for the first time, a strong affection for the man who has saved his life. Thornton treats his dogs like his own children and Buck responds to the adoration and obeys all his commands. Even when Thornton asks him to jump off a cliff he obeys him before he is stopped by Thornton. Even though Buck is happy with Thornton, his fighting wild instinct remains strong. He starts fighting in defense of Thornton and soon earns the reputation throughout Alaska for faithfulness and fierceness. Many a times he saves the life of Thornton – once when he steps in to stop a fight in a bar and the fighters lashes out at him; once when he is thrown off a boat and gets caught in a fierce torrent. That winter a strange urge grasps Thornton and he challenges that Buck can start a sled with a thousand pounds loaded on it. A man named Matthewson, who has become rich in the gold rush, bets a thousand dollars by saying that Buck will not be able to perform the task. Though in doubt himself, Thornton accepts the bet and borrows the money from a friend. Hundreds of people come to watch and the betting goes on. Initially Matthewson is confident and he keeps adding to the amount. But once Buck is harnessed, he pulls the sled a hundred yards breaking through the ice. The crowd cheers in admiration and even Matthewson joins the applause.
After paying off his debts with the money he has earned from the bet Thornton, with his friends Pete and Hans and the dogs, sets towards the east. They wander in the wilderness and finally reach a shallow place in a valley full of gold. The men start earning thousands of dollars a day in the gold mine whereas the dogs have nothing to do. Buck craves for the wild desires and one night he suddenly feels the call from the forest. He rushes through the woods and makes friendship with a small wolf. Though the wolf encourages him towards the forest, remembering Thornton he returns back to the camp. But again the call of the wild haunts him and he keeps away from the camp for days together. Buck has now two identities – one a sled dog in Thornton’s camp and another as a wild hunter in the forest. Once, on his way back to the camp, he senses some calamity. His feeling is justified when he finds two of Thornton’s dogs dying on the track. As he approaches the camp he sees Hans coved with arrows lying face down. He sees the Yeehat Indians dancing in the ruins and charges towards them cutting their throats and killing several. As the Indians disperse, Buck finds the rest of his camp, including Thornton, dead. Buck mourns for his dead master but feels proud of having killed the Yeehats. Broken by death he heads towards the forest again when he hears the call of the wolf. He finds a pack of wolf who fight with him. But latter the wolf who had befriended him approaches him and Buck joins the wolf group. The Yeehats watch the group and finds a difference in the local breed of the timber wolves as the years pass by. They narrate the story of a Ghost Dog that runs in front of the pack, singing and leaping. They also recount the haunted valley, where Thornton lies dead and the evil spirit resides and where, every year, Buck comes and mourns beside the stream and then rejoins the pack of wolves in the forest.