Everybody loves a good society. Wait, no, "secret" -- everybody loves a good secret. That's probably why secret societies are so fascinating - there's nothing more tantalizing than a secret you can never know the answer to. And since the truth is inevitably disappointing compared to whatever you can cook in your head, we turn to movies for our secret society fix. Here are six of the most terrifying movie secret societies - guaranteed to never produce a President of the United States.

The Freaks, "Freaks"

Some secret societies are hidden in plain sight - like the one in Tod Browning's cult horror classic "Freaks." The membership requirements are twofold: One, you have to be a circus or carnival performer. Two, you have to possess some kind of extreme physical deformity, ranging from dwarfism to being The Human Torso (that is what it sounds like). Luckily for prospective members, this secret society isn't shy about bringing number two on by force.

The League of Shadows, "Batman Begins"

Here we have a more traditional secret society, one that quietly shapes the progress of nations in secret. Can't complain about them too much, though, since in addition to plotting the course of human history to their own ends, they also indirectly brought us Batman. And who doesn't love Batman? And, fittingly enough, it's Batman who finally brings down the League after their leader (played by Liam Neeson) picks the wrong city to destroy.

Opus Dei, "The Da Vinci Code"

The central plot point of Ron Howard's religious conspiracy thriller "The Da Vinci Code" has to do with "the greatest cover-up in human history" - that Jesus Christ had a son with Mary Magdalene and who went on to form a sacred bloodline that continues today. Harmless, right? Well, the people in charge of keeping the secret don't think so - and Opus Dei will go to any lengths, even violence and murder, to keep it from getting out.

The Others, "Night Watch"

The mythology of the 2004 Russian blockbuster "Night Watch" is far too complicated to get into here, but suffice it to say that there are these beings called The Others, some light and some dark, who are charged with keeping the forces of good and evil balanced out for eternity. There are werewolves, shapeshifters, vampires, psychics, the whole deal. And they're right in front of us, occasionally getting into giant CGI slugfests but mostly staying underground. It's both scary and completely awesome.

Project Mayhem, "Fight Club"

Project Mayhem, like many secret societies, started out completely innocently: As an underground fight club for disillusioned thirty-somethings to beat the snot out of each other in a supportive environment. But thanks to the vision of Tyler Durden, things quickly got out of hand, with acts of violence and terrorism eventually following. What happened to just beating each other up, man? What happened to that?

The People of Summerisle, "The Wicker Man"

It's easy to keep your secret society a secret when the entirety of the population lives on a secluded island. What becomes somewhat difficult is finding a virgin to sacrifice to your pagan gods and goddesses - but the people of Summerisle in the 1973 horror classic "The Wicker Man" come up with a pretty novel solution to that one too. First rule of any secret society: Think outside the box.