Son rented that on Bigpond movies the other night. Very enjoyable, and worth the two hours to watch it. You are left guessing all the way through. It's also a very good comment on those who live outside of society. It presents as a re-creation of a true story. I had to go and look it up afterwards just to make sure. The book, from which the movie was made, (same name) has received great reviews and is a best seller. Well worth the watch!

Don't read the reviews before watching, or reading, some may give away an interesting twist.