Just as Joséphine returns to Paris with Youssouf, Souleymane disappears. Judge Vargas, who was in charge of Gilou's infiltration, decides to cut his losses.
Chief Inspector Laure Berthaud and her team of tough uncompromising cops are called in to investigate a double murder. The ensuing investigation soon reveals the tensions within police team and their legal colleagues.
Told a guilty secret, Laure plots to correct matters, but must elude Tintin's dogged detective work. Josephine struggles to prove her client's claims in court. Roban must confront a colleague, and a health issue.