Tells a fascinating and unsettling true story, and does so well, without pretending to have all the answers.

At first rather annoying in its heavy emphasis on reenactments, this movie ultimately proves fascinating, simply because the complicated, highly dramatic tale it tells still almost defies belief.

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

Exactly the movie you think it is, but not the movie you want it to be.