The summer trial begins under a stifling sun at the Palace of Justice, drawing a large crowd of journalists and spectators. The narrator sits in the dock, observing the anonymous faces of the jury and chatting briefly with journalists who treat his case as a slow-season curiosity. After the judges enter and open the session, the preliminary procedures conclude and the court begins calling witnesses to the stand.
The prosecution's questioning shifts focus away from the crime itself and heavily toward the narrator's behaviour following his mother's death. Testimony from the asylum director, the concierge, and Thomas Pérez highlights the narrator's calm demeanour, his refusal to view his mother's body, his smoking, and his drinking of coffee at the vigil. The prosecutor seizes upon these details to portray the narrator as cold and devoid of normal human feeling, eliciting murmurs of disapproval from the audience and making the narrator feel universally hated.
Character witnesses including Céleste, Masson, Salamano, and Raymond testify in his defense, but their attempts to help are repeatedly undermined. Céleste calls the tragedy an unfortunate accident, while Marie recounts their date and moviegoing on the day after the funeral. The prosecutor leverages this timeline to brand the narrator a moral monster whose actions surrounding his mother's burial directly mirror his callous crime. Although his defense lawyer protests the shift in focus, the prosecutor links the two matters as essential evidence of a criminal heart.
As the court adjourns for the day, the narrator is transported back to his prison cell. During the journey, the familiar sounds and smells of the summer evening evoke fond memories of his past life before confinement. He recognizes that familiar city pathways can lead to prison just as easily as they once led to peaceful sleep.