‘Three Identical Strangers’ is a provocative, at times troubling documentary that tells a story truly stranger than fiction. A rumination on the nature/nurture divide, blind coincidence and the limits of ethical behavior, it’s a non-fiction film with enough of a hook to prove instantly compelling to general audiences.

The film begins with the quirky, inadvertent reunion of twins separated at birth, discovered when one of the brothers attends a college only to be mistaken for another who looks and acts extremely similar. After news reports about their meeting spread, a third brother is discovered, raised by a completely different family from very different circumstances.

The brothers become a kind of cause célèbre, appearing on daytime television talk shows and showing off remarkable similarities presumably hardcoded into their DNA. At 19, they become the talk of the town, traipsing through New York and basking in the attention. This is a terrific if two-dimensional human interest story, a fun and frivolous separated-at-birth tale that fits in between stories about economic and political ennui on the nightly news.

If that was the whole story, ‘Three Identical Strangers’ would be a mere curiosity, certainly not a full feature documentary. It’s the second half of the story, which is best experienced within the context of the film and not read about ahead of time, that elevates the documentary in a journalistically compelling direction. Given the evergreen fascination with true crime stories, this takes that tact in a very different direction, finding through some remarkable and abhorrent machinations a manipulation of these brothers’ lives that’s the stuff of horror fiction.

It’s a bit frustrating how this dark turn is telegraphed early. Still, director Tim Wardle and the CNN Films team are adept at crafting a film that’s entirely accessible while still delving into the harrowing implications the circumstances unearth. Talking-head interviews are interspersed with old 8mm footage and contemporaneous television appearances, providing both distance and context to the past through modern reflection.

Once the bombshell is dropped, the film has a difficult time sustaining its impact, often using repetition of previous material to emphasize its central points. This makes for a degree of redundancy that’s perhaps beneficial to the casual TV viewer capturing this through word-of-mouth rather than someone who has chosen to see it in a cinema. For that latter person’s benefit, however, a wider scope to the imagery and interviews is welcome. Given its genre-film like storyline, there’s a visceral thrill to be shared in the collective experience of seeing the movie in a room full of strangers.

‘Three Identical Strangers’ isn’t flawless, but it certainly does justice to this odd, haunting tale. As it plays out, one can’t help but empathize with both the highs and lows the brothers undergo, riding along as they come to terms not only with their relationships to each other but their connections to the past. A better story than a film, there’s still plenty to recommend about Wardle’s film, which is sure to be one of the most talked about documentaries of the year.