In May 1997 , Marrs ' investigation of UFOs , '' Alien Agenda '' , was published by HarperCollins Publishers . The paperback edition was released in mid-1998 . It has been translated into several foreign languages and became the top-selling UFO book in the world . '' Publishers Weekly '' said : Marrs shows little discrimination , overemphasizing dubious phenomena like remote viewing and crop circles , and giving nearly equal weight to ludicrous pretenders like Billy Meier ( who claimed close encounter with Pleiadians ) and sophisticated commentators like Jacques Vallée . Marrs even devotes a chapter to theories that the moon may be a UFO , and he refuses to rule out obvious frauds like the alien autopsy tapes . But if rigorous analysis escapes Marrs , little else does ; this is the most entertaining and complete overview of flying saucers and their crew in years . In early 2000 , HarperCollins published '' Rule by Secrecy '' , which claimed to trace a hidden history connecting modern secret societies to ancient and medieval times . This book also reached '' The New York Times '' Best Seller list . In 2003 , his book '' The War on Freedom '' probed the alleged conspiracies of the September 11 attacks and their aftermath . It was released in 2006 under the title '' The Terror Conspiracy ''
September 11 attacks
September 11 attacks
Jim Marrs