A series of bomb and poison attacks shakes the North Sea island of Langeoog. Who are the seemingly random attacks targeting in this summer vacation paradise? Are the rumors true that the "Four Gang" is behind it – a group of old men who sit at the train station every day, grumbling about tourists and wishing for the days when the island belonged to the locals? Island police officers Lüppo Buss and Insa Ukena are in the dark. They cannot rely on the help of Chief Inspector Stahnke this time, as he is tied up with a murder investigation in Leer. Waldemar Wallmann, head of a temporary employment agency, was found dead in the Bingum yacht harbor. Did he really just cross paths with a boat thief? Stahnke feverishly searches for clues and would much rather be on Langeoog with his girlfriend Sina Gersema. When he also learns that Sina's ex-boyfriend Mari...