The dogs were worn out due to the fact that in less than five months they had traveled 2,500 miles, and they had five days of rest.
The dogs were sold from Francois and Perrault to Hal, Charles, and Mercedes.
Charles whipped the dogs, for not being able to carry the heavy load that was on the sled.
They spilled their load then the dogs ran away, they were brought back by townspeople; they got rid of half of the load and added six outside dogs and they still couldn’t bear to move the load at a “reasonable” pace.
Charles, Hal and Mercedes were inexperienced and they were underfeeding the dogs and expecting them to go twice the distance. Dub was the first to go, Hal shot him with the revolver. After that, Hal traded the colts revolver for horse hide and the horse hair damaged the dogs insides and unfortunately, Billee fell and could not rise.
Thornton came and threatened Hal about whipping Buck then rescued Buck and took him out of his misery.