Is there really a secret elite, the true rulers of our world, meeting once a year to empower presidents and dictators, moving wars and economies around like pieces on a chessboard? This is the premise of journalist Jon Ronson's Them, the book version of his Channel 4 series The Secret Rulers of the World.

Spending time with various extremists (the main criterion for their inclusion being that they have been labelled as such by others) Ronson stumbles upon the fact that nearly all of them believe in a small world-ruling elite. Many of the usual suspects are here: Muslim clerics and gun-toting white supremacists as well as characters closer to home, among them David Icke and Ian Paisley, who refers to Ronson in jocular tones as "The Jew".

As he ambles through this world where nothing is quite what it seems, Ronson's foppish demeanour and laid-back style belie a strong, enquiring mind. While on a trek to Lisbon with 'Big Jim Tucker', a passionate campaigner against what he sees as the people-manipulating New World Order, Ronson does indeed unearth strange goings on at the meeting place of the latest Bilderberg get together. He is subsequently followed by a green Lancia - not quite a black helicopter but sufficiently slick enough - driven by a man in dark glasses. Ronson only learns later, to his horror, that Tucker's magazine Spotlight is a magnet for Anti-Semitic campaigners. In fact, Ronson discovers himself to have been duped and used on a number of occasions. There is indeed something inherently sinister about these people's potential for manipulation and deception, though the book's frequent hilarity - for above all this is a very funny book - comes from the limitless capacity of these same individuals to deceive themselves.

Them isn't just a riotous farce, however. The story of Rachel Weaver (whose mother and brother were killed by FBI agents during the "Siege of Ruby Ridge") is treated in a clear-eyed but sensitive way. Ronson judges the tone perfectly here, while at other moments he lets the buffoons speak for themselves. In this respect his investigations achieve true fortean dimensions, maintaining the delicate balance between scepticism and open-mindedness essential to a fortean approach

Described as a 'romp into the heart of darkness', Them is funny and thought-provoking, and should sit comfortably on the shelves of any fortean.