All detectives search for clues and take testimonies when working a case. Ghost detectives are no different. And they have an advantage: They can depose other ghosts — the actual victims.

Robert and Clothilde's current interviewee occupies a tiny cemetery in the depths of the Pyrenees. Alone since her burial over a decade ago, she willingly tells the detectives about the circumstances around her death.

Louise's story sets Robert, Clothilde, and Captain Evian on the path to uncovering new facets of the conspiracy responsible for so many deaths — bringing them one step closer to justice.