Rainy Spirit is a filly still looking for her true destiny in life. She is an alicorn, daughter of Princess Luna and Star, a changeling who recently was murdered. When Luna and Celestia discover the changelings are searching for "their" princess, they send Rainy to live with Twilight for protection. With her new disguise, Rainy Spirit will make friends, fight her enemies, and bond with all of the Elements of Harmony. As she and Twilight grow closer, though, will Twilight realize she may have bit off more than she can chew by agreeing to protect her?