Caroline Taman only intended to go for a short hike in the mountains close to the town where she had recently moved. But when she blunders into what she assumes are drug dealers in the woods and flees from them, she is drawn into the company of a man whom she soon learns is not a man at all. Because he heard her unwittingly crying to Christ for help, he feels he can reveal what he is to her. As he helps her elude her pursuers, he tells her his name is Sylvan, and he is a spirit of the wilderness. He is also a lover of humanity beyond the capacity of a normal person as well as a devout Christian. The two of them soon learn the criminals she met have far more sinister plans than dealing drugs. They intend to sell a unique form of radioactive rock to terrorists, but they have no idea just how lethal the stones are. The criminals are soon forgotten as Caroline and Sylvan find themselves in an impossible death race to keep the radiation of the rocks from spreading through the world. Throughout their struggle, Caroline's wonder deepens as she learns more about Sylvan's love for humanity and devotion to God. It blossoms in her own soul until she can accept the hardships and danger with his inhuman tolerance. Her own deep Christian convictions grow with it, and she abandons her life to their struggle.