When fossil-hunter Jim Dragon is on his way to Bear Creek to sell his latest discovery, he goes to the aid of a woman in distress, Elmina Fay. Unfortunately, Pierre Dulaine takes advantage of the situation and steals his fossils.

Jim vows to reclaim his property and Elmina offers to help him, but only if he'll do something for her. She has heard a tale about the bones of a winged horse being found nearby and she wants Jim to find Pegasus for her.

At first, Jim is skeptical about embarking on such a mission, but before long he discovers that the truth behind the tale is even stranger than he could ever have imagined.