The recurrent enigma of the flying saucer is finally solved when an aerial pieplate is caught with its exhaust down by the F.B.I. of 2007. Hero Sam penetrates the contaminated area, brings a "master" back- a gelatinous gray mass which attaches itself to a soldier's body and controls his thought processes. Sam and his girl spot further landings, plan a counter campaign and eventually are able to rid the solar system of its parasites. Exciting, even if it exacts a strong stomach.