Unicorns of Balinor: Search for the Star (Book Five)

The evil Shifter regains some Deep Magic by stealing the Indigo Star from the sleeping giant dragon Naytin and tries to destroy the unicorns of the Celestial Valley: their bright colors and their powers start to fade. Arianna, the Sunchaser and others set out to take the Indigo Star from the Shifter and return it to the dragon.