Buck, a powerful shepherd dog, is disbarred from his comfortable life in California as the pampered pet of Judge Miller, when he is stolen by the assistant of the Judge’s gardener and sold off to pay for his gambling debt. From California’s Santa Clara Valley the location shifts to Seattle where Buck is shipped. On his journey he is harassed and is provided neither with food or drink. When he is finally released from the crate he confronts more misery and is even beaten up so that he learns to respect the club. He is bought by a pair of French-Canadians who take him to Alaska and train him as a sled dog there. Buck learns to survive the cold winter nights and adapt himself to the situation by following his teammates. He even develops a rivalry with the lead dog Spitz and eventually he defeats Spitz in a major fight. The other dogs close in and Spitz is killed leading Buck to become the leader of the team.
The sled dog team, including Buck is then sold off to a Scottish half breed man who works in the mail service. The load that the dogs carry is very heavy and the journey becomes tedious and extended. After some time the situation becomes so worse that the dogs fail to overcome their tiredness and fail to proceed with their trek. Buck is then sold to a trio, Hal, Charles and a woman named Mercedes, who are looking for a fortune by finding gold. They are inexperienced in the art of sledding and struggle to survive in the Alaskan wilderness. The situation of the sled dogs becomes miserable in their company and finally Buck falls in the hands of John Thornton who rescue him from the ill-treatment of his owners. Though Thornton warns the trio against crossing the river, they ignore his advice and precede further leaving Buck behind. The ice gives way and the trio, along with the dogs, falls in the river.
Thornton nurses Buck back to health and Buck starts loving his new master and becomes devoted to him. Buck saves the life of Thornton twice and is praised for his faithfulness. He is taken by Thornton on various trips in search of gold. In one such trip a man bets Thornton over Buck’s strength. Buck helps Thornton win the bet by breaking the ice and pulling the sled hundred yards. The bet money is used to pay off the debts of Thornton. Thornton and his friends return to the camp and continue with their search for gold and Buck starts exploring the wilderness around. He befriends a wolf in the forest. One night when he returns to the camp he finds every member, including his master, being killed by a group of Yeehat Indians. In rage he attacks them and kills many. He buries his past with the death of his master and responds to the call of the wild by following the pack of wolves in the forest. But every year he comes to the forest to mourn his master’s death and then retreats into the wild responding to its call.
The novel is often classified as children’s literature because of the animal protagonist, but the maturity of its subject-matter makes it valuable for the older readers as well. Major themes that are included in the novel are ‘the survival of the fittest’, ‘civilization versus nature’ and ‘fate versus freewill’.