In the folds of the Lot valley, a new breed of lords claims to rule over the Cahors vineyard. Pierre-Yves Pellegrin, a powerful businessman and owner of Château Champ-Grèze, reigns supreme over the appellation. Within shooting distance, Château Hébrard has just been acquired by another industry captain accompanied by a dubious manager. Ambitions are boiling, and the thirst for power is never satisfied. When oenologist Benjamin Cooker and his assistant Virgile arrive in the region to monitor the fermentation of the latest harvest, there is a smell of counterfeit aromas and ignoble rot pervading the lands of Quercy. A sordid crime, an unidentified corpse, heirs in identity crisis, a weary commissioner, tarnished reputations, and dishonored honors... What mystery lies in the tannins of the black wine? What secret does vat number 13 hold?