Julien (Guillaume Canet) receives a call from Marie, (Mélanie Laurent) his ex-wife asking for help after Mathys (Lino Papa), their 7-year-old son has been missing. He arrives at the camp, the police shows him the tent where it’s believed that the boy was abducted. However, the police can’t do anything because there are no leads to follow, no witnesses to interview, and no suspects to question.

Marie thinks that Mathys probably ran away because he was upset when she told him she was pregnant with Grégoire (Olivier de Benoist), her new boyfriend. Julien left his family three years ago to pursue his career traveling around the world as a geologist, so he has no idea what’s going on with Marie’s new family. But Julien doesn’t believe that his son could just take off without saying anything, especially not in the winter like this.

The evidence at the camp has led Lieutenant Verrier (Mohamed Brikat) to believe that the boy was abducted, although there’s no contact or ransom demand from the perpetrator. The police already set up checkpoints and issue missing children alert in the system.

Julien learns that Grégoire doesn’t seem to like Mathys from the camcorder found in Marie’s house after she asked Julien to get photographs of Mathys for the police. Later that night, Julien drives to return house’s keys to Marie at Grégoire’s house but he’s told that Marie already went to bed. Things get escalated when Grégoire keeps talking about his new house plan for Marie and his new-born son, he doesn’t seem to care about Mathys at all. Julien gets furious and accuses Grégoire for abducting Mathys, then beats the crap out of him.

Julien brings Grégoire to the police station to be investigated. But instead Julien is arrested when Lieutenant Verrier sees Grégoire in the back of the car. There’s no evidence that Grégoire has anything to do with do with the missing of Mathys. All Julien’s theories are quickly dismissed by Verrier who tells him to stay out of trouble and let the police do the job, as it turns out Grégoire has a solid alibi for the night that Mathys was reported missing.

But Mathys has been missing for two days, Marie becomes more frustrated, she fears that Mathys may be dead by now. Julien receives a call from a female colleague telling him that the police came to the headquarters asking questions about him, which upsets the employers as they don’t want police to snoop around their properties and documents. She warns him that his phone will be bugged and traced, the police are trying to connect if his work was related to the abduction. Julien spends time scrubbing through all videos again. Unable to trust the police, Julien follows a conceivable lead on his own hoping to find and save is his son.

MON GARÇON is a slow-burn French thriller film directed by Christian Carion. Guillaume Canet only received the outline of the story like where he was supposed to be, who would be on a particular scene with him. This method somehow manages to captivate and surprise us as well as his performing partners whom also didn’t know what Guillaume was going to react to a certain situation with his improvised dialogue and emotions. Although the film gives us a new kind of thriller vibe, it’s not entirely unpredictable.

Guillaume’s performance really holds the film together as he takes us on a frantic quest through breathtaking scenery of Autrans to find his son and brutally punishes those who are responsible with a blowtorch and a golf club.

MON GARÇON premiered at Festival du film francophone d’Angoulême on August 23, 2017. The film was theatrically released in France on September 20, 2017, and as Video On Demand on January 19, 2018.