Clement è un novizio cresciuto tra frati e canti gregoriani. Arguto e colto, aiuterà il capitano della polizia, Elli Taleb, nelle indagini di omicidio.

La presenza di Clement nella squadra si rivela determinante in un caso di omicidio in un tempio protestante. Nel frattempo, Alex chiede il trasferimento a Lione.

Una docente viene trovata morta nell'aula magna della facoltà di Maryam. Elli scopre che la vittima aveva discusso con un professore di Maryam.

Camino de Santiago. Eric Massol, owner of a cottage, is found on the way killed by a bullet. A priori the 6 hikers who slept at the cottage have nothing to do with this death. But Elli asks Clement to accompany them to Valmagne, Clement's monastery and the next step on the way. On the one hand, Clement walks with the group and notices some strange behavior. On the other, Elli is destabilized in her investigation by a discovery that will undermine the ideal image she had kept of her parents who had been dead for 15 years. Elli and Clément will eventually meet in Valmagne to solve a case where the culprits and victims are not who we think.

While Mathias and Clément come to deliver products from the vegetable garden of Valmagne in a restaurant in the hinterland of Montpellier, the owner of the establishment falls on the lifeless body of a second of kitchen. Elli learns that the victim died after poisoning...

During the renovation of the Abbey of Valmagne, a foreman was found dead.