Re: Heavenly Creatures by Peter Jackson
Fair point, and by itself I don't think it is. After all, a lot of people have rather complex imaginary worlds going on in their heads...
Ultimately, it's the real world events that prompt the murder and not the interior monologue - I was interested to note that none of the imaginary characters, despite being a violent bunch, actually remarks on it, let alone suggests it. That said, the film gives me the impression that the closeness of the real and imaginary worlds makes the progression from thinking about murder to actually doing it all the easier, especially in the way that the real world is filmed as blurring into the imaginary one.
The film could have told the same story without any fantastical elements, and dismissed the imaginary world as a sideline. However, it wouldn't have been such a good or revealing film.