Anthropologist Stanley Shephard is brought to an arctic base when explorers discover the body of a prehistoric man who has been frozen for 40,000 years. After thawing the body to perform an autopsy, scientists first attempt – and succeed – to resuscitate the "iceman". The dazed caveman is alarmed by the surgical-masked figures; only Shephard has the presence of mind to remove his mask and reveal his humanity and somewhat familiar (bearded) face, permitting the iceman to settle into a peaceful recuperating sleep. The scientists place the iceman in an artificial, simulated environment for study, though the caveman quickly deduces that he is far from home. Shephard believes that the caveman's culture may provide clues to learning about the human body's adaptability, citing ceremonies such as firewalking. Other scientists see the potential in studying the caveman's DNA and his survival in the ice, for possible "freezing" of the sick until treatment is possible. Shephard defends the caveman's right to be considered a human being and not a scientific specimen. Despite opposition from the others, Shephard initiates an encounter with the caveman. Shephard names him "Charlie" after the iceman introduces himself as "Char-u". Shephard and Charlie bond, but it becomes obvious to the anthropologist that Charlie misses his world. A linguist is brought to the Arctic base, and the scientists make progress communicating with Charlie. Shephard introduces Charlie to colleague Dr. Diane Brady. Assuming that the woman is Shephard's mate, Charlie makes chalk marks which indicate that he likely was a married man with children before he was frozen. Shephard strives to understand what motivates Charlie and why he survived being frozen. At one point, Shephard begins to sing "Heart of Gold", inspiring Charlie to sing one of his own songs. Charlie's line drawings in the ground resemble a bird, matching body markings on his chest. When the base's helicopter strays over the roof of Charlie'