Pistol-packing Mary Outlaw and her spinster aunt Cora have tickets to ride the Santa Fe train on a sight-seeing excursion from Topeka, Kansas to Pueblo, Colorado. This is Aunt Cora’s gift to Mary. The women share a love of adventure, and Mary is hoping her aunt has an answer on how to avoid getting married. She intends to live life unrestrained on this trip because it may be her only chance unless she can convince her father to let her choose her own husband. A future of cooking and babies is not the life she wants.