The fine line between friends and enemies blurs as Ellis Cady sets out to reach the new frontier of post-Civil War America.

After waiting out winter at the Cady ranch in southern Missouri, hope blooms in the Spring of 1866. Ellis receives news of a mysterious man arriving in St. Louis. Will she find her father alive and well, or finally put his memory to rest?

Grasping at the illusive promise of her father's whereabouts, Ellis is distracted by the intrepid trick rider, Jimmie, a woman who rides with Levi Jack's Wild West Exhibition. Then, talk of reinstating a messenger service akin to the Pony Express rekindles a faded dream. Since the war's devastation, important letters and messages still need to get through a western landscape governed by Indians and outlaws. When an untimely epidemic threatens, Ellis finds herself back in the saddle, a young woman and her horse on a perilous trail.