Following the Guernon affair (Les Rivières Pourpres) in the mid-2000s, the emblematic Captain Pierre Niemans is transferred to the head of the Central Office against Blood Crimes (OCCS). This new confidential unit deals with the most complex cases, where clues are few and serial murders must be solved as quickly as possible. It is during a particularly difficult mission that Niemans stumbles upon his best student and spiritual daughter, Camille Delaunay. Specialists in the dark side of the human soul, an explosive duo with no less original methods, Niemans and Camille are sent to the four corners of France, to regions where legends, landscapes and traditions are mixed with complicated murders and increasingly nervous and dense investigations. Independent, efficient, and of a rare courage, this tandem of shock melts in the decoration, not hesitating to sleep at the inhabitant’s to better perceive their secrets… As borderline as each other, they are sharp, funny, effective – and dangerous.