This is a must-see and one of the best documentaries - and films - of this year.

While it doesn't offer any answers, it both thrills and makes you think.

It's funny, it's tense, it features two great performances from two actors and the director expertly creates a web of odd tension where you actually don't know what is happening for the majority of the run time.

It's simply great fun, a winsome film and an occasionally over-the-top luxury fantasy that never flags.