In a Stuttgart public park drifts the corpse of leach-breeder Anja Schafmeister. She seems abused, making husband Max Schafmeister the prime suspect, as insists client Georg Vanderlo, who hides initially having an affair with her. The leach farm assistant Beate Jacoby is an extreme animal rights activist, who instead of destroying used leaches planned a "retirement pond" in the pond, compromising the farm's license and possibly threatening the rare natural indigenous species. Shy Max, who practices unusual para-medical therapies, including leaches, also was blamed by a deceased patient's husband, who turns up furiously.
—KGF Vissers