The body of a man is found hanging by his feet in the cemetery of Montjoyer. Alex Lazzari, a local gendarme, is in charge of investigating but he must team up with Alicia Tirard from the Grenoble research section. The collaboration starts badly: Alex has cornered Alicia's delinquent son a short time before. As for the investigation, the man was not directly identified but afterwards, the autopsy led them to think that he could be a monk from the Abbey of Notre-Dame d'Aiguebelle, near the cemetery. The body was indeed identified: it was Brother Yves. The congregation produces a liqueur from plants. Legend has it that an elixir of immortality is at the origin of the liqueur. Could the death of the monk be linked to his activity within the abbey?