Jack Thornton has trouble winning enough at cards for the stake he needs to get to the Alaska gold fields. His luck changes when he pays $250 for Buck, a sled dog that is part wolf to keep him from being shot by an arrogant Englishman also headed for the Yukon. En route to the Yukon with Shorty Houlihan -- who spent time in jail for opening someone else's letter with a map of where gold is to be found -- Jack rescues a woman whose husband was the addressee of that letter. Buck helps Jack win a $1,000 bet to get the supplies he needs. And when Jack and Claire Blake pet Buck one night, fingers touch.