Ludovic and Nathan discover that the violent boyfriend of Nolwenn, the third victim, is the son of a jeweler from Brest... Could it be the mysterious murderer with the ring? While Nathan pursues this lead, Ludovic observes with horror the disappearance of Parvana and Sam: Mélanie, by provoking a meeting with Parvana in 1998, has changed the future! The young woman feels terribly guilty: how is she going to make up for her mistake?