Ethan and Eva Thomas live on a sheep ranch with their father and aunt. As an avid amateur photographer of local wildlife, twelve year old Ethan deplores hunting and guns of any kind. As an animal lover, he maintains a small "trauma ward" in the back of his father's barn where he nurses wounded animals back to health, then frees them into their natural habitat.

Eva, his ten year old sister, inherited more of her father's genes and as a consequence, loves guns and hunting and aspires to be a big game hunter and explorer in the Alaska wilderness. Although both enjoy ranch life and the great outdoors, their different natures are constantly at odds with each other.

Then, then, is the story of how a gentle-hearted boy and his tomboy kid sister meet the challenge of dealing with a mysterious white wolf and a terrifying grizzly bear aptly named, "Ol' Lucifer" who roams the foothills of the Grizzly Mountain Range.