Sea girl Aquina has always felt different from the rest of the sea people on Rulantica. Shortly after her twelfth birthday, she learns the unbelievable: she has a twin brother. Mats, a human boy! And he is in great danger. There is no stopping Aquina, she must find her true family before it is too late. Mats has been raised in an orphanage since he was picked up on the beach as a foundling. He has always been afraid of the sea and the water. But he has no idea that he will soon be plunged into the greatest adventure of his life! With their meeting, Mats and Aquina fulfill a centuries-old prophecy of the Norse gods - and this can mean salvation, but also doom for the entire island world of Rulantica ... Discover the world of Rulantica already now interactively on: explore-rulantica.de and from November 2019 in the new water adventure resort of Europa-Park Rust. The book is based on a story world by MackMedia GmbH & Co KG.