THE IMPOSTER is one of those too-strange-to-be-true tales that's like manna for documentarians. In the early 1990s, 13-year-old Nicholas Barclay disappeared from his Texas home, only to turn up four years later in Madrid. Or so his family thought. Or so they maybe thought. Because the "kid" in Spain claiming to be Nicholas Barclay was really 23-year-old con artist Frédéric Bourdin, who just happened into the right story, a US passport, and a seemingly new identity.

Bart Layton's documentary lays this all out in the first few minutes. There's no trick where, midway through the movie, that particular rug is pulled out from under us. (Layton leaves that for other twists.) Instead, the bulk of The Imposter is devoted to Bourdin's methodical technique. He's half student of human nature, half fast-thinking showman. Bourdin tells his own story, looking the audience directly in the eyes. He's funny, and charming, and disarmingly honest—you can almost see why he fooled an entire family into thinking he was their lost child.

In fact, Frédéric's tale has enough salacious pulp that it remains interesting despite Layton's heavy-handed filmmaking. Layton overdoes it with the reenactments, staging whole scenes and getting clever with the way he syncs Bourdin's real narration with the teenage actor playing him in flashbacks—to such a degree I started to fear that maybe I was getting conned, too. I understand why Layton chooses to withhold some information until it's dramatically opportune to reveal it—that's part of the mystery. But it's hard not to feel manipulated, especially once the director concocts a bullshit ending to try for one last "Gotcha!" If you can set such nagging questions of technique aside, though, The Imposter's a true crime yarn that really does have to be seen to be believed.