While teenager Bess Truly sits alone in her room at her family ranch in Three Winds, New Mexico, she gets a surprise visit from the mysterious federal agents that she has seen in the past. They come with a message. Her father has gone missing in the desert!With her horse Electra, Bess goes looking for her father. She discovers much more, including a group of exiles from a distant land, and that's not all. The refugees are running from a pursuing group of angry and dangerous soldiers from the moon, who want to get their escapees and take them back into their cold sterile world out in space.Bess, with help from her friends, her father, and a new group of unique and skilled people, must find a way to save all the men, women, and children who are trying to escape their prison on the moon. Using her father's flying craft, the Starlighter, and her mother's invention, her Zap-Gun, Bess will fight a desperate battle in the heat of the desert to save the day and stop the last of the evil moon men from their nefarious deeds.