Buck is a huge four years old Scottish Sheppard-Saint Bernard cross breed who protected the household of Judge Miller's estate. His strength and intelligence made him leader of all the family dogs.
At this time, the gold rush had started and big, strong dogs like Buck were high in demand. Manuel, the gardener needed money to pay for his family and his gambling, so he took Buck to the railroad station and he was sold. For two days Buck traveled to Seattle with nothing to consume. There, a man beat him and he learned he could not be at ease. He was put with other dogs who he came to learn much about. His body became hard and all the cuddly, housedog personality dissapeared. He was lef with wolfly instincts that taught him to steal food from others, dig under snow for warmth, and survive without much food. He became leader of the pack and they lost fear of Spitz, the mean dog. Francois and Perrault were angry at this. One night, Spitz and Buck fought. Spitz lost his edge and Buck threw him to the ice where the other dogs killed him. Buck fought his was to leadership and the team became one. Buck was known for his teamwork and great leadership. .
They over worked the tired dogs, making them slower. At night, Buck would dream of Judge Miller, killing Spitz, and his ancestors. They were sold to mercedes, Charles, and Hal, who overworked them and overfed them, and were clueless about caring for dogs. Nine dogs died and they finally quit at John Thornton's house.
As Buck was going to get the whip, John stopped them. They moved on and fell in the ice leaving Buck behind with John. After traveling so far, John gave him love, food, and nursed him back. Trust and love was surely gained between the both of them. Buck saved him from drowning and pulled a ton of flour to win John $1,600 to share with his partners. John refused to sell him because he loved him. They paid their debts and went east into mining Country where they shared a cabin and mined for gold.