Avsnitt 4

The body of a mutilated woman is found along a road. For the Invisibles brigade, the killer's relentlessness and madness are beyond doubt. While Duchess begins to have doubts about her ability to cross paths with Ben on a daily basis, she crosses paths with the handsome Alexis, an old acquaintance... Darius, for his part, confronts Chistera about Leïla, his adoptive sister . He understands that she is in grave danger, in a high-stakes criminal case. At the same time, we discover two fiber optic installers who are making the rounds of Lille homes. While one is flirtatious and insistent with the women he meets, the other is more reserved, shy... What's the connection?