To Helen,

with love

Donald E. Keyhoe, who relates here his investigation of the flying
saucers, writes with twenty-five years of experience in observing
aeronautical developments.

He is a graduate of the U.S. Naval Academy at Annapolis. He flew in
active service with the Marine Corps, managed the tour of the historic
plane in which Bennett and Byrd made their North Pole flight, was aide
to Charles Lindbergh after the famous Paris flight, and was chief of
information for the Aeronautics Branch, Department of Commerce.



Author's Note

ON APRIL 27, 1949, the U.S. Air Force stated:

"The mere existence of some yet unidentified flying objects
necessitates a constant vigilance on the part of Project 'Saucer'
personnel, and on the part of the civilian population.

"Answers have been--and will be--drawn from such factors as guided
missile research activity, balloons, astronomical phenomena. . . . But
there are still question marks.

"Possibilities that the saucers are foreign aircraft have also been
considered. . . . But observations based on nuclear power plant