Since the 1980s, some 10,000 crop circles have appeared, seemingly by magic, in England and 25 other countries. The author takes readers to the scene of the enigma, before, after, and during the appearance of a fresh circle and relates: how to distinguish a hoaxed circle from a genuine one; what the magnetic field disturbances might mean; what time distortions observed at crop circles might mean; how sound, light, and microwave energy may be involved; how a theory of music may account for their creation; what the crop images mean.