With the investigation gaining attention, tensions rise in Saint-Michel. Sarah confronts Lieutenant Virginie Taylor about the similarities between Katie's disappearance and the earlier case of Odile Lambert, a local girl who vanished years before.
Virginie reveals that new forensic evidence connects Xavier to Katie's belongings, while local authorities prepare a large search of the surrounding woods. Yet Captain Jerome Ricard appears reluctant to reopen Odile's case, warning Virginie against pursuing connections that could damage the town.
Refusing to step back, Sarah begins investigating on her own. Her search leads her to people who were connected to Odile years earlier, uncovering troubling accounts of how that case was handled - and how some leads may have been ignored.
Meanwhile, cracks begin to appear within the investigation itself. Virginie secretly reviews the old case file and discovers that several key details were never fully resolved. The revelations raise uncomfortable questions about people close to her.
As volunteers, students, and police comb the forest for evidence, Sarah notices strange relationships between several individuals involved in the search - connections that seem too coincidental to ignore.
Back at the school, tensions among the exchange students reach a breaking point. One student reveals disturbing messages sent to Katie shortly before she disappeared, pointing suspicion toward someone previously overlooked.
As new suspects emerge and personal secrets surface, Sarah uncovers another unsettling detail: on the night Katie vanished, she made a phone call to someone Sarah knows very well.
Moments later, a violent confrontation erupts that dramatically changes the course of the investigation.
