Buck comes to love and grow devoted to Thornton as he nurses him back to health. He saves Thornton when the man falls into a river. After Thornton takes him on trips to pan for gold, a bonanza king (someone who hit it rich in a certain area) wagers Thornton on the dog's strength and devotion. Buck wins by breaking a half-ton (1,000-pound (450Â kg)) sled free of the frozen ground, pulling it 100 yards (91Â m) and winning US$1,600 in gold dust. A king of the Skookum Benches offers a large sum to buy Buck, but Thornton has grown fond of him and declines. While Thornton and his friends continue their search for gold, Buck explores the wilderness and socializes with a timber wolf from a local pack. One night, he returns from a long hunt to find that his beloved master and the others in the camp have been killed by a group of Yeehat natives. Buck eventually kills the natives to avenge Thornton, and he then is attacked by an entire pack of wolves. Buck wins the fight, then finds that the