Appel farmer Marko Hansen in the idyllic village Altes Land marshes is found poisoned in the local cooperation's nitrogen-filled storage antechamber, locked-in with one of the magnetic keys handed to the many members, including small apple-yard owners like detective Oskar Schütz, a mate in the Big Apple pub's Skat cards game club. The hothead bachelor annoyed many locals. The murder must have been a local, with access to the local voluntary fire brigade as he used a mask missing from their truck. Unidentifed, someone escapes after breaking into Marko's home and uses his boat. Marko's brother Kai fell out with him rowing over an inherited orchard. His recent testament allotted nearly everything to the son of "Big Apple" publican Thorsten Braker and his wife Serena, who admit she was among Marko's countless conquests, he probably was the biological father. Then the cops find a link to recently dumped drug contraband, which means acute danger for them too.