Mystery surrounds Miss Becky McCoy when she shows up alone and unexpectedly at the Campbells' ranch house in Southeastern Arizona Territory. Fourteen-year-old Cody Campbell befriends the quirky girl in the bright pink, feathered hat and becomes enthralled with her as he learns that she is deficient in basic spelling and reading skills, but she possesses the ability to communicate with horses and has the skills to cure them of their ills. Over the course of three days, Miss Becky's adventures involve Cody, ailing horses, bucking broncos, outlaws, and Apaches. Ultimately, Miss Becky reveals to Cody that she is terrified she will lose her horse-whispering abilities as she becomes a woman. Only time will tell if her fear is unfounded, but another birthday is upon her.