Personally affected by the discovery of a drowned body, Chief Inspector Werner Drews gets the impression that the summoned colleagues from the criminal police are all too quick to close the case. Together with some friends, particularly Willi, a former Foreign Legionnaire, Drews attempts to clarify the crucial background of the case that is so important to him. His acquaintance with a scientist working on a secret project makes him realize that the local economy and industry are repeatedly exposed to attacks from industrial espionage and data theft. The kidnapping of a lawyer ultimately leads the friends onto the right track. With a wink and inspired by the titles of well-known blues songs, the author describes the course of the investigation against the backdrop of the small Upper Bavarian town of Burghausen.