On their very first day of vacation, Lilly and Nikolas find a message in a bottle on the beach of Norderney – with a mysterious task: Whoever finds the smallest sailor will receive a reward! The siblings are thrilled. Eagerly, they search for clues while exploring Norderney with Mom and Dad and visiting the neighboring islands of Juist and Langeoog. Lilly and Nikolas discover that you can see all the way from the lighthouse to Borkum and that Kluntje crackles in the cup. They learn how to peel crabs and the best way to remember the order of the planets, which animals live in the mudflats, and how people used to bathe a hundred years ago. Whether they visit the shipwreck at the eastern end, observe seals, frolic in the waves at the bathhouse, or listen to Dad tell the story of the brave sea woman Mine and her racing seal Selma: The mystery of the message in the bottle.