With 4 crystals restored, the team is on a mission to find the remaining 3! But Sunny is struggling with being separated from the group. They know that the sooner they solve this puzzle, the sooner they can all work together again! But even after all 7 Moonbow Crystals are restored, Rainbow High is still trapped in a sad, blue gloom! What's going on? With the help of an unexpected guest, will they be able to uncover the secrets of the past and restore Rainbow World?