I stand on a very neutral platform on the subject of crop circles, I've no spiritual feelings about them but think that they are both spectacular and very special things. I also know people who have a completely opposite opinion to my own and I also know of people that this documentary names as 'hoaxers'. So I watched this from the stand point that these circles are art and that the humans (yes, humans) that make them are talented and capable people who never claim ownership. This is not just because what they do can be classed as criminal damage but because the joy they get from watching people's reactions to the masterpieces they have created and that is enough for them.
Sadly the 'secrets' promised in the title of this documentary never materialise. They treat Peter Sorensen (the only maker they could get to actually talk to because no one else involved would even want to broach the subject on camera) as a silly, sad old man. Stick on some comedy music and show footage of him pulling faces all you like, the truth is that he came to Wiltshire to research the subject as a 'believer' but actually found out on his own terms that the patterns are made by people, deciding not to take the road of discarding evidence and blocking out anything that he didn't want to hear.
The resultant film never comes to any any conclusions, spends endless tracts of time padding out their footage with night watches in random fields, uses the phrase '... which was a decision we would later regret' way too much for no good reason and ends with the film makers basically saying 'we've wrung all we could out of it and have come to absolutely no conclusion whatsoever'.
A vanity project that didn't have enough material to fill it's 1hr 22 min runtime.
Don't bother watching it. You'll learn nothing.