In Jessie's last visit to the Fairy Realm she discovered a part of the Realm she had never seen before. And she helped the rainbow fairies find a lost treasure.

Now the Realm is in tremendous danger. And so is the human world! The evil creatures of the Outlands are planning an attack. So Jessie must make an impossible decision. Should she try to save the human world, or the Realm? She knows she can't save both. Or can she -- with the help of the powerful unicorns? But the unicorns are such secretive creatures. Can Jessie possibly convince them to help?