Four years have passed since the Driss Assani case. Yoann Peeters has moved, he's not a cop anymore. He tries to take some distance in an attempt to forget the tragic death of Sebastian Drummer. But his past catches up on him quickly.

Jasmina Orban, the psychologist who took care of him back in the day, comes back to find him. She's working with a new patient : Dany Bastin, a young man on probation. He is accused of a horrible crime, but she is convinced he's innocent. Yoann is the only person who can help her. But he's reluctant, he promised himself he would never investigate again...

Été 2018. Musso, un petit village perdu dans les forêts ardennaises. Le docteur Orban, la psychiatre qui s’occupait de Yoann Peeters, suit un nouveau patient : Dany Bastin, un jeune homme de 27 ans en réinsertion. La thérapie suit son cours lorsque Dany est accusé d’un nouveau meurtre, celui d’Astrid Du Tilleul, une riche bourgeoise chez qui il travaillait comme jardinier.

Convaincue que Dany est innocent, la psy demande à Yoann Peeters de l’aider. Mais ce dernier est réticent. Il n’est plus flic, et il s’était promis de ne plus jamais enquêter…

La dottoressa Orban indaga su un omicidio che coinvolge un suo paziente. Yoann Peeters accetta controvoglia di aiutarla, sconvolgendo ancora una volta la propria vita.

Akcja ma miejsce cztery lata po wydarzeniach związanych z zabójstwem Drisa. Inspektor Peeters opuszcza Heiderfeld i zostaje wykładowcą kryminologii.

Yoann Peeters se trezește prins într-un alt caz de crimă, deoarece fosta sa psihiatră îi cere ajutorul pentru a demonstra nevinovăția unui pacient.