A quick-thinking Vincent helps Mia evade Violetta and her cronies, who are determined to get their hands on Mia's mysterious book. Still unsure if she can trust Vincent with the truth, Mia disappears to Centopia in time to find Lyria in need of urgent help. She also witnesses an amazing event: the birth of a golden-horned unicorn who may be the key to restoring hope to Centopia.