Gambling debts. A father facing execution. An unknown son. A secret lover. Four women all have ties to a prosecutor who is killed in his hotel room.

As Captain Raven launches a murder investigation, Léonie proves her worth and Henri extends an invitation to the annual picnic, ruffling family feathers.

With the gala approaching, Delaunay pressures Giulia, Léonie questions Edouard's confession and Angèle's decision to stay with Eugénie enrages Blanche.

A mysterious pendant at a crime scene captures Raven's attention. Marthe plants seeds of doubt before Henri makes a confession to his family.

In the wake of another tragedy, Giulia is forced into a lie. Jean offers a weak alibi, while Léonie faces both helpless grief and bitter disappointment.

Léonie, Blanche, Eugénie and Giulia decide there is only one way out, just as Raven believes he has cracked the mystery of the Riviera murders.