In a small western town, spunky ex-city girl Lucky forms a tight bond with wild horse Spirit while having adventures with best pals Pru and Abigail.

A mare in Spirit's herd is about to give birth. Lucky signs up Abigail and Pru for Prescott Charm School so they're prepared for the Governor's Ball.

The girls set out on a dangerous trip to help a seized Tuckapaw teenager escape from a speeding train and get back to his faithful horse.

Lucky's classmates call her "teacher's pet," so she vows to cause trouble on the upcoming field trip.

A railroad bridge is destroyed by an earthquake, so Lucky and her pals need to alert the passengers on a train that'll be there at any moment.

Lucky and the gang find gold, so they recruit Julian, Lucky's sly cousin, for help, but their potentially huge cash-out goes awry.

With the help of Lucky and her friends, Aunt Cora gets back in the saddle to ready herself for a ride. Meanwhile, Spirit's herd is endangered by a nearby mountain lion.