Eleven-year old Nicholas Barclay disappeared during a sleepy San Antonio afternoon in June 1994. Almost four years later, word of the blond-haired, blue-eyed boy’s sudden re-appearance in Spain came as a miracle—and for Frédéric Bourdin, a 23-year-old French con man known as “The Chameleon,” it was. Despite his swarthy complexion and French inflections, Bourdin was able to convince Spanish authorities, FBI agents, and almost the entire Barclay family that he was the missing boy, engineering a web of lies that landed him on U.S. soil posing as a Texas high school student.

The Imposter re-tells and recreates that drama (memorably recounted in an August 2008 New Yorker article by David Grann), staging the story’s juicier bits with actors mouthing actual lines from interviews with Bourdin and the Barclays. It’s a twisting, darkly comic narrative that constantly cocks an eyebrow at its audience: the interviewee’s apparent bewilderment and confusion infuses the documentary with the tension of a thriller.

Director Bart Layton opens with the impossible tragedy of a beautiful child disappearing: bright-eyed Nicholas is shown manning the family camera at birthday parties, alive in every sense of the word. Rather than rehashing the family’s despair, however, Layton kneads in Bourdin’s murky past by letting the imposter tell his own version of the events, and his efforts towards “being acceptable” to authorities. Part of the film’s allure is how unapologetic and honest our ever-grinning villain is, despite the despicability of his actions. When the con clears the red tape and the fateful reunion between the real Nicholas’s sister and the stranger posing as her brother takes place, Layton intercuts home video of the moment with the reminiscence of those involved, and we feel the respective longing and dread on each side of the embrace.

Once back in Texas, Bourdin is welcomed back into the fold of a family he never had. Their willingness to accept the drastic physical changes between this son and the one they remember is shocking. Do the Barclays believe Bourdin’s inventive and horrifying lies (he claims to have been abducted by foreign military officials, and subjected to rape and torture for sport), or are they simply willing to suspend disbelief in order to reclaim a lost son? Bourdin, for his part, seems happy enough at first. Layton’s rendition of Bourdin’s assimilation into American culture is overlaid with The Doobie Brothers and Cat Stevens—a bizarre burst of Americana interrupted only when a diligent FBI agent recounts taking Bourdin to a trauma specialist who finds no truth in his stories.

Layton’s lets his characters (particularly a cowboy private eye who boasts of discovering Bourdin’s deception by looking at his ears) make their own insinuations. Chief among these is Bourdin’s accusation that the Barclays murdered their son. But regardless of whom you choose to believe, Layton’s long takes of an empty Texas landscape and suggestive close-ups of each Barclay sitting in silence drive home the uneasiness that still hangs in the air.

Featuring a notably high production value in its reenactments, The Imposter is a film first, defined by yawning desert panoramas, Andrew Hulme’s razor-sharp editing, and Layton’s ability to bob and weave around a definitive conclusion as to what really happened. What is certain, however, is the bone-chilling uncertainty with which Layton positions the ambiguities and true-crime mystery of Bourdin’s eerie descent into a family’s private world of grief. Like Bourdin’s remorseless epilogue, we are left to accept the secrets as they stand.