The killer takes two new victims: Monica, a young woman, and Yacine, a fellow officer and friend of Clovis. For Lise, it's high time Clovis explained himself. Who is this woman Mathilde, who claims she lives with Clovis and is the mother of his child? Incapable of responding, Clovis leaves home and takes up temporary residence at police quarters. Faced with the new murders, the prosecutor decides to appoint a superior police officer to oversee the lake killer case. It doesn't take Diane Varella long to suspect that someone on Clovis' or Lise's team must be leaking ...