Buck the dog was a hunting dog at his owners farm. He lived in an aristocratic family that loved him, and he was the favorite dog throughout the farm. But, one night, one of the owner's workers sold Buck to a dealer for the Yukon Gold Rush. Buck's fur was the perfect kind for that of a sled dog. He was put on a train and never saw his home in Santa Clara Valley again.
Buck gets put into a sled team at Yukon, Alaska. When he first gets there, there are many challenges, such as staying warm at night, and keeping strength. But, Buck eventually overcame these challenges and trials,and worked his way to the second spot on the team. He was fond of most of his fellow sled team, except for the leader. He was harsh, and even killed Buck's friend.