John Thorton is final owner of the Buck and ideal owner.
John Thornton saves Buck from Hal, Charles, and Mercedes.
In the Call of the Wild movie, John Thornton is secretly gay. He has an affair with his partner, Charles.
When Buck becomes more of a wild animal, Thornton and his friends and dogs are killed by the Yeehats. Buck avenges their deaths by killing some of the Yeehats, while the remaining ones fled, calling him the "Evil Spirit".