A mysterious crash over the French Alps sets off a meticulous, escalating investigation that tests the limits of truth and corporate interests. An Atrian 800 aircraft plummets from the sky, killing everyone on board, and Mathieu Vasseur, an air safety investigator for the Bureau of Enquiry and Analysis for Civil Aviation Safety, is tasked with dissecting the cockpit voice recorder. The initial read points toward a forced entry into the cockpit shortly before the tragedy, nudging him toward a terrorist theory. He presents his early conclusions at a hastily convened press conference, shaping the public narrative even as questions linger.
As the investigation unfolds, Mathieu’s supervisor, Victor Pollock, vanishes, leaving Mathieu to steer the final report. He encounters troubling inconsistencies in the voice recorder and notices a voicemail from a passenger recorded before the crash, which complicates the terrorist hypothesis. His doubts meet firm resistance from Philippe Rénier, the agency’s head, who remains unwavering in the don’t-look-back stance of the agency leadership. The pressure to confirm a straightforward cause grows, even as Mathieu senses that something deeper and more troubling might be at play.
The trail grows thornier when Mathieu discovers an odd clue at Pollock’s personal space: an envelope containing Pollock’s street address, a sealed window, and a wonky sense that someone is watching. Returning later with determined resolve, he finds Pollock’s house abandoned, its secrets sealed behind closed doors. In a moment that blends tenacity with reckless risk, he breaks in, scavenges for anything useful, and nabs the dashcam SD card. What he uncovers through a sequence of footage shifts the investigation onto a different path. A late-night rendezvous with Xavier Renaud—head of Pegase Security, a company that designs on-board aircraft communication systems—reveals a potential cover-up that looms over the entire inquiry.
A pilot’s testimony introduces a troublesome possibility: the Atrian 800 carried unresolved quirks in its rudder’s anti-stall system, yet it had still earned an air-worthiness certificate. Mathieu turns to a more hands-on approach, obtaining flight data for simulations. His wife Noémie, employed by Atrian, becomes an unwilling focal point when the data disappears from her control, triggering tension at home. Mathieu’s insistence that the data must be scrutinized strains his relationship as Noémie accuses him of jeopardizing her career. In parallel, Philippe Rénier transfers Mathieu to other duties, a move that only fuels the investigator’s determination to uncover the truth.
The plot thickens with new information from the press and political circles. An investigative journalist from Mediapart reveals the name David Keller, a former Pegase employee once arrested for attempting to hack aircraft communications, and Keller is discovered to have been aboard the doomed Atrian 800. As Mathieu gears up to hand over his files, he notices a crucial alteration in Pollock’s version of events. A GPS coordinate is embedded in the updated file, leading to a pond behind Pollock’s house and to a trove of hidden evidence—an original voice recorder that holds the key to the real sequence of events.
Using Pollock’s equipment, Mathieu analyzes the recovered recording and reconstructs a dramatic truth (shown in a flashback): Keller did not intend a fatal crash; his aim was to expose vulnerabilities in Pegase’s systems by taking control of the airplane’s computer. The attempt spiraled out of control, and neither Keller nor the pilots could regain control, culminating in disaster. The revelation reframes the tragedy as a manufactured and concealed failure rather than a simple act of terrorism, exposing the fragility of the aircraft’s on-board systems and the ethical compromise at the highest level of oversight.
The film crescendos with a chilling late-stage reveal. Pollock appears in a video confession—an admission that he tampered with the voice recorder under duress, forced to conceal faults in Pegase’s systems by Renaud’s coercive influence. As Mathieu watches the incriminating footage, two figures enter Pollock’s home, signaling an imminent threat. He escapes just in time, but not before uploading the documentary recordings to Noémie, ensuring that the truth endures beyond his own safety. The escape ends in tragedy when his car, allegedly hacked to mirror the plane’s loss of control, veers off the road and crashes, sealing Mathieu’s fate.
In the final act, Noémie seizes the moment to reveal Pollock’s confession to a wider audience. At the Paris Air Show, she quietly integrates Pollock’s testimony into the event’s visual presentation, where industry leaders and journalists witness the shocking reality of a cover-up. The public and media response erupts in real time, casting a new light on Pegase’s practices and the integrity of the investigation. As the spectacle unfolds, authorities close in on Renaud, whose influence and power are undercut by the mounting avalanche of evidence. The truth comes at a cost, and the film leaves the viewer with a stark meditation on the hidden costs of corporate pressure, the fragility of technology, and the perilous intersection of ambition and accountability.
