The Call of the Wild is a novel by Jack London about Buck, a St. Bernard-Scotch Collie who, after being stolen and mistreated by numerous owners, ends up in a dog-sled team in Canada. After fighting and killing the lead dog, Spitz, Buck becomes the leader. Buck is traded amongst various outdoorsmen until finally being rescued by John Thornton, who recognizes his exceptionality. After Yeehat natives kill Thornton, Buck avenges his death and enters the wild to live with a timber wolf. Loyalty, cruelty and nature are themes throughout.