How to describe this documentary -- your jaw will drop.

"The Imposter" was done in 2012. A 13-year-old boy, Nicholas, disappeared from his family home in San Antonio, Texas in 1994 and turned up three years later in Spain. The person claiming he was Nicholas was an imposter -- and an obvious one. In fact, his eye color was different from Nicholas. The family, however, welcomed him with open arms and seemed to believe him.

"Nicholas" -- who spoke English with an accent -- appeared on a TV news show and while filming it, the investigator who had been sent to find him for the interview became suspicious and was convinced that he was not Nicholas.

This opened up a new set of questions: Why had this family accepted such an obvious imposter as Nicholas? And if he wasn't Nicholas, who was he? This is a knock your socks off documentary, absolutely fascinating and very well done. See what you think.

While it's fascinating to have a documentary in such detail on both sides of a criminal act, it's most interesting aspect is watching the development of a mad man unfold in just a single shot spread over the whole film. At first, Frederic Bourdin appears charming and approachable as he explains his old thought processes with a smile. Over the film's progression, in which we're treated to Man On Wire-esque re-enactments, it's clear he actually has no remorse and his pride is unsettling, especially as this case is just one of the many. Although the film does underwhelm in the end slightly, that can't be helped for it's a documentary, the best aspect is the slick photography in both the interviews and re-enactments making it look incredibly cinematic. The Imposter is a really well constructed film that makes its unbelievable story work and keeps a consistent level of intrigue and anxiety throughout, even if in an ideal world, it should be building up to a finer payoff.

8/10

THE IMPOSTER, a much-lauded documentary that was all over the media when it came out last year, tells an intriguing mystery and is a complete surprise, because you honestly don't realise that people can be as gullible as the ones here. It tells an odd tale indeed, and as is the case with these things, to tell much about the story would be to spoil it.

Let's be clear, this is not perfectly made; it's nowhere near in the same category as the excellent BLACKFISH or the shocking TALLHOTBLOND I saw last year. The reliance on staged dramatisations is tiresome in the extreme and the story is a little slow to get going, so that the ending feels rushed. However, the flaws can be readily overlooked, purely because the tale told is so outlandish, so remarkable, so unbelievable, that you just know it has to be true. Watch it and see for yourself.