Buck returns to find the camp of his Master, Thornton, looted by robbers; and finds Thornton and his companions dead. This is heartbreaking to Buck, as Thornton has been the first owner who has been kind to him since his kidnapping from his California home.
Buck's sorrow gives way to rage, and he hunts down the robbers. He finds the robbers and kills most of them. The few that escape included yeehats.
Buck then answers "The Call of the Wild" and joins a wolfpack, quickly becoming the Alpha Male. Buck's knowledge of human ways enables the pack to outwit human traps, making them seem like ghosts. The yeehats add that to what he did to the band of robbers and now they consider him an evil Ghost Dog.