Killer by the Lake

Lise Stocker, head of the Paris Crime Bureau, returns to her hometown to care for her sick mother. Upon her return, she hears that local teenager, Chloe, has vanished during a local celebration. The mystery disappearance ignites old memories for Lise - fifteen years ago her two best friends, Ana and Marion, disappeared during the very same event. Is there a connection between the two incidents?

Lise and Clovis find a third corpse and deduce that the woman was probably the killer's first victim. Meanwhile, Marianne's nursing assistant Marthe is corresponding with a man on a dating site who is actually the killer.

Remi Bouchard is arrested over Chloe’s disappearance, just like he was fifteen years ago. Lise is not sure he is guilty, especially when he informs her that the former prosecutorial investigation against him was biased and certain elements were left out. The investigator at that time was none other than Lise's own father, who has since committed suicide. Who is lying and who is telling the truth?

Several locals become suspects in the case. Clovis and Lise's inquiries appear to indicate that Remi Bouchard is telling the truth and the investigation carried out 15 years earlier was falsified.

Unimpressed by local efforts to catch the lake killer, the prosecutor appoints a new senior officer, Diane Varella, to oversee things. Lise wants Clovis to explain himself, but he won't respond.

Suspicions soon points to Chloe's former teacher, Nicolas Mazaud. Evidence against Mazaud, who also taught Ana, Marion and Lise is getting stronger and stronger. Was Clovis wrong to release Remi Bouchard who appears to be a step ahead of everyone in solving the mystery puzzle? And does a letter of confession really mean Lise and Clovis have found the culprit?