Benjamin Lebel is flattered that his youth-days poetry about the Cathar castles are to be published by a small firm in the Languedoc department Aude, so the drives there with assistant Silvère, who was promised a castles tout. They stay with Lebel's old friend, oenologist and former fellow 1960s revolutionary Janny Verniaud, who now leads a cooperative for biological wine-growing, but her young partners -especially hothead Arthur Gassard- are tired of her stickler obstacles to profitable production. The Montepelleir professor who piloted the Lebel poems projects, Janny's former colleague, has been killed in a car crash, which Benjamin finds suspicious even before his home is found ransacked, so he digs in the professor's other projects too.