Is it possible than flying saucer are being manned by an ancient Earth race? Do members of an underground civilisation walk among us, monitoring scientific advances, sabotaging strategic techo-development and silencing successful investigators? Has the US Navy really succeeded in teleporting a warship from Philadelphia to Norfolk? And did some of the crewmen on that ill-fated ship burst into flames while others lapsed into invisibility in front of their families and before patrons in a crowded bar, and are there men still confined to psychiatric wards as a result of that experiment?  Before scoffing or pooh-poohing, consider this:  the Allende Letters have been the subject of an investigation by the Office of Naval Research, and it was believed the letters were destroyed in a freak fire - but it seems only copies were destroyed, not the letters themselves.