When a soon-to-be teenage monarch is forced to flee her unstable county during a military takeover, a rural Louisiana teen attempts to help her make the transition to rural American life until order can be restored back home. Rosalinda Marie (Demi Lovato
) was about to become queen of Costa Luna when chaos swept through the streets, and an agent from the Princess Protection Program whisked her away to safety. After receiving her new identity at PPP headquarters, "Rosie" learns that she will temporarily be living with the family of the agent who just rescued her. At first, young Carter Mason (Selena Gomez
) isn't quite sure what to make of her new houseguest. All Carter knows is that "Rosie" is posing as her cousin from Iowa, and that it's going to take a lot of work to help the princess fit in at her local high school. At first the two girls seem to share little in common except for their age, though when "Rosie" nominates Carter for homecoming queen over the vehement objections of popular girls Chelsea and Brooke, the ice begins to thaw. Realizing that "Rosie" is more than just an air-headed princess from an unknown country, Carter begins brainstorming for a means of helping her new pal regain her throne, no matter what the risk.