In search of images of her favorite painter Walter Bertelsmann, Inga Tarmstedt, a young sculptor from Worpswede, travels to the North Sea island of Baltrum. There, she befriends Lena Tarmstedt, the granddaughter of her guesthouse owner. However, her stay is overshadowed by a catastrophe: Lena's grandfather, the moody Hinrich Claassen, who had arranged to meet a friend to collect beach treasures, is found unconscious on the beach and later dies in the hospital. Soon, doubts arise about whether he truly died of natural causes. Shortly thereafter, a young man is discovered dead on the beach. Do island police officer Michael Röder and his colleagues from the mainland have to deal with two murders? Inga takes care of Lena and tries to learn more about the famous painter's stay on the island. But someone seems to be opposed to her inquiries.