Throughout the modern UFO era， thousands of honest scientists and informed laymen have seen through the official denials， the suppressions， and the whitewash -- and realized that， indeed， we are not alone. To them， author Jacques Vallee， the world s most renowned UFO expert， presents a tantalizing question. What if -- just if -- these alien visitors are Not from other planets? What if they have always been among us?What if we can finally prove the case to which so much evidence points: That they have lived on earth for centuries， perhaps， from the beginning of time. That they may inhabit another dimension， a dimension so startlingly different from our own that our consciousness lurches to experience it religiously.At once exhilarating and persuasive， Vallee s brilliant insights include a metaphysical odyssey through some of the most mystifying incidents in religious and mythological lore.The miraculous visions of the Lady of Fatima in 1917.The "cloudships" said to have visited medieval France.The ancient Tzeltal Indians of Mexico kidnapped by flying half humans.With his unparalleled knowledge of thousands of close encounters. Vallee -- the UFO authority celebrated in Steven Spielberg s Close Encounters of the Third Kind -- constructs an eye-opening， yet ultimately irresistible theory: one that reveals the shocking reality of the ever-present， ever-powerful interdimensional aliens of Earth... and humanity s persistent inability to understand them.