The underwater kingdom of Aquamarina is in trouble because the enchanted Music of the Sea has stopped playing--so Thea and the Thea Sisters, together with their friend Will Mystery set out on a dangerous mission to find the Sea Violin which will restore color and life to the Kingdom.

At head of title: Geronimo Stilton. Geronimo Stilton and Thea Stilton are fictitious characters. Translation of: Il segreto delle fate degli oceani. Based on an original idea by Elisabetta Dami.