Living deep in the Pacific Northwest forest, a young orphan named Pete has an unlikely friend: a giant, green, flying dragon named Elliott. For years, they've lived an idyllic life, hidden from the world. Pete, who ended up in the forest following a tragic car accident that claimed his parents' lives, evaded discovery with the help of Elliott's ability to become invisible. They share a bond of friendship, living comfortably in the forest, with Elliott acting as Pete's guardian and companion. Their peaceful existence, however, is soon disrupted when a logging operation encroaches on their secluded home.

Grace, a kind-hearted forest ranger, discovers Pete and is intrigued by his wild tales of a dragon friend. Initially skeptical, she comes to realize that there may be truth to his stories after she encounters Elliott herself. Her father, who has long claimed to have seen a dragon in the woods, suddenly finds his stories validated. As the town gets wind of Elliott's existence, Pete's life changes dramatically. He struggles with the desire to protect his secret and the longing to rejoin human society, while also confronting the increasing threat posed by those who wish to capture Elliott for their own ends. The encroaching civilization not only poses a danger to Pete's way of life but also to the survival of his incredible friend.