Grandma is getting forgetful. For a year now, Sönke and Maria have been living together on the North Sea island of Föhr. However, the peace comes to an end when Sönke's underage cousin Jade comes to visit. Instead of the well-behaved girl from before, they are faced with a moody goth girl. Grandma is also a concern, as she is becoming increasingly forgetful, really forgetful! Then a spectacular criminal case occurs on the island, and the police send a commissioner from the mainland, someone Maria knows from the past - her attractive ex-boyfriend. But in the Frisian Caribbean, all problems eventually resolve in their own unique way...