Hanauer, Michaela: Rulantica - Hidden Island Rulantica 1

Aquina is a mermaid. She has always felt different from the other merpeople on Rulantica. Shortly after her twelfth birthday, she finds out something incredible: she has a twin brother. Mats, a human boy! And he is in great danger. For Aquina, there´s no holding back: she has to find her real family before it´s too late. Ever since he was found on the beach as a baby, Mats has been brought up in a children's home. He has always been afraid of the sea and of water. What he doesn´t know is that he´ll soon be diving into the biggest adventure of his life! By coming together, Aquina and Mats are fulfilling a centuries-old prophecy by the Nordic gods - this could be a chance to save the island world of Rulantica, but it could also mean its total destruction ...