Cassandre takes on a new job in a provincial police station.

An educator for delinquent teens is found brutally murdered in her home.

On the Mont Blanc massif, a group of hikers enjoy a beautiful afternoon and suddenly, a series of gunshots are heard and an entire family is massacred; Commissioner Cassandre investigates the case.

Parisian cop Florence Cassandre moves to Annecy and takes a new job investigating crimes in the Haute-Savoie region.