Emma Taylor is bound for Dallas, but her path leads through Gemini Canyon - a place not even the most foolhardy travelers will go. Anthony Baxter, a worn stagecoach driver, agrees to take her - but Emma has no inkling of the supernatural forces living in the canyon's depths.
Emma Taylor gets off the train in Morning Glory, a dilapidated clapboard town in the burgeoning frontier. The townsfolk react with fear when she announces that she's determined to make her way to Dallas - the only path South is through Gemini Canyon, they say. And nobody goes through Gemini Canyon.
Anthony Baxter observes her determination, and offers her a ride in exchange for her skills with her shotgun. The two ride into Gemini Canyon. Soon, a mysterious figure pursues them - it evades their shots. The horses become frenzied, and the wagon crashes.
When Emma comes to, she sees Anthony throw a knife over her head, into the chest of - herself. The THING, wearing Emma's face, whips the knife back at Anthony, hitting him. Emma and Anthony trade shots, knocking the creature back for a moment, and make their escape.
Anthony is passing out from loss of blood, but Emma helps him on the horse and the two ride for Dallas.