The Songs of the Sea festival is about to start, but disaster has struck! The royal musicians will be performing, but all their instruments have disappeared! Harper and her friends use the flying umbrella to come to the rescue, and that very night they start hearing beautiful music coming from Melody Bay. Will they have the courage to walk along the pitch-black smugglers' tunnels passing under the sea to find out who has stolen the instruments? A captivating adventure story all about friendship, creatures of the sea and magic.