Buck, a powerful and pampered St. Bernard-Scotch Collie, lives a comfortable life in California until he is stolen and sold into the harsh life of an Alaskan sled dog. As Buck is thrust into the brutal environment of the Yukon Territory during the Klondike Gold Rush, he faces a series of challenges that awaken his primal instincts. The once domesticated dog gradually transforms, learning to fight for survival and asserting his dominance over other dogs. His journey is marked by encounters with both kind and cruel humans, but it is his connection with John Thornton, a compassionate prospector, that brings out Buck's deepest loyalty and love.

As Buck adapts to the wild, he becomes attuned to the call of the wilderness, experiencing a profound internal struggle between his loyalty to Thornton and his instinctual pull toward the untamed. He becomes a legendary figure in the wild, embodying the spirit of the wolf that has always resided within him. Thornton's tragic death ultimately frees Buck to fully embrace his wild nature. He joins a wolf pack, answering the call that has been growing louder in his heart, and becomes a revered and respected leader, forever marked by the journey that took him from civilization to the wild.