This book owes its appearance to the Freedom of Information Act, adopted in the United States in the 70s, and the persistence of its author, Bruce Maccabee, who, with the help of this Act, gained access to FBI archives. A renowned expert on optical physics, Dr. Maccabee presents his interpretation of more than one and a half thousand secret FBI documents, while proving that this organization and its director John Edgar Hoover took both UFO reports and eyewitnesses of events associated with this phenomenon quite seriously. Using Only government documents, that is, documents whose source is well known, allowed the author to concentrate on their content without being distracted by proving their authenticity. Acquaintance with this fascinating book allows us to conclude that UFOs actually exist and may well be interplanetary spaceships.