Set in the small frontier town of Miradero, a 12-year-old girl named Fortuna "Lucky" Esperanza Navarro Prescott, who had recently relocated from the city, encounters a wild kiger mustang named Spirit Jr., the son of Spirit and Rain from the 2002 movie Spirit: Stallion of the Cimarron. When Lucky is on the train travelling to Miradero. The horse is caught by wranglers and brought to Miradero to be “broken in”. Lucky immediately bonds with the stallion and frees him from his pen. Lucky also makes friends with Prudence "Pru" Granger and Abigail Stone. Pru owns a talented and proud palomino horse called Chica Linda, and Abigail owns a friendly and goofy pinto horse called Boomerang. The three girls call themselves the PALs and go on many adventures with their horses.