Lyle Swann is a successful off-road racer who mistakenly gets sent back in time 100 years. When a band of outlaws robs Swann of his motorcycle, he's forced to outfox the gangsters and give in to the seductions of a gorgeous local lady. With only his smarts and a map from an Exxon station, Lyle must try to make it out of the Old West alive and find a way back to modern times.

Professor "Johnny Longbow" Salina, a man who really knows his stews, introduces Paul Carlson to the practical-joking Kathy Nolan. Paul and Kathy seem to hit it off rather well but, during a meteor storm, a meteorite fragment strikes Paul, burying itself deep in his skull, which has the unpleasant side-effect of causing Paul to mutate into a giant reptilian monster at night and go on murderous rampages. It turns out that this sort of thing has happened before, when Professor Salina rediscovers ancient Native American paintings detailing a similar event many centuries ago. Kathy, however, still loves Paul, and tries to save him.