Promise of the Unicorn (Unicorns #4)

Arica's mother has been kidnapped by her evil uncle. Could this be his revenge for her protecting the Book of Fairies? It will take all of Arica's courage – and the help of all her friends – to find and rescue her mother and save Bundelag from Raden's evil clutches. She's counting on the unicorns, but Arica doesn't know about the ancient pledge and the limits of the unicorns' power. Just how far can magic take her?