In the idyllic Sauternes in the Garonne Valley, the finest sweet wine in the world is produced. Right here, in the midst of the harvest season, a young winemaker is found dead in her wine cellar. The toxic gas produced during fermentation has killed her. But is that the whole truth? While the local police consider it an accident, Commissaire Luc Verlain trusts his instincts and launches an investigation. However, in the small community, he encounters a wall of silence. Apparently, the winemaker made some enemies with her fight against pesticides and adulterated wines. And then there’s a secret whose roots reach further back into the past.