Heldt's 'fatherly' publican and family friend Karl-Heinz “Carlo“ Funke is found next to the corpse of his landlord Erich Baumann. Unlike commissioner Grün, Heldt is determined to prove his buddy's claim of innocence despite a violent money row the evening before. Autopsy shows poisoning by exclusive claret, hidden behind Carlo's cooler. Heldt examines dodgy third chess player Sven Lattbeck, and neighbor Dr. Paul, and is suspended, the clock ticking. Although evidence piles up, Heldt keeps examining the neighbors, with some risky help from Ahmed and unexpectedly from prosecutor Bannenberg, who even fakes a syndrome to distract Dr. Markus Paul, the resumed drug provider, while relationships to Spanish cleaner Estefania prove key.