They act in the shadows, they are extremely secretive and they practise ancient rituals. Secret societies play a far larger role in our everyday lives than we are aware of. Publications like those of bestselling author Dan Brown have brought them back into the limelight. The three-part documentary, ‘Secret Societies’, accompanies historian Dr. Marian Füssel on his search for clues surrounding history’s most famous secret societies and conspiracy theories. Behind closed doors, cliques of the world's most powerful men form societies so secret and controversial that their very names spark fear in our hearts and minds: the Freemasons, the Illuminati, Skull and Bones. What are the intentions of these secret societies? Are the members of these brotherhoods the innocent victims of mudslinging conspiracy theorists or are they untouchable elitists who control the world? One way to find out is to explore their mysterious and covert histories.