The tenth adventure in the shimmering Unicornia series, featuring a magically refreshing swimming pool! It's summer in Unicornia, and Claudia and her friends can't wait to visit the Rainbow Pool! Here, the swimming goggles are magical and the bottom of the pool hides a whole world of secrets. But Claudia is too embarrassed to tell her friends that she doesn't know how to swim underwater. Can she conquer her fear and discover the treasures of the deep? Find out in this shimmering adventure!.