This early adaptation of the classic Jack London novel follows Jack Thornton (Clark Gable) as he travels across Alaska during the Klondike Gold Rush. When he finds another Yukon-bound man, who treats his sled dogs cruelly, Jack purchases a dog named Buck, who leads the way toward the gold. But Jack reconsiders his journey when he finds Claire Blake (Loretta Young), a woman recently abandoned by her husband in the Alaskan wilderness, and the couple develops a romance.