Ever hear of an interocitor? No? Well, don't be surprised - neither had Cal Meacham, electronics engineer and chief of research at Ryberg Instrument. Nor had Cal ever heard of a catherimine tube with an endiom complex of plus four. Yet those, and other equally bewildering apparatus, were offered for sale in the catalogue from Electronic Service Unit 16. Unfortunately, there wasn't a single clue in the catalogue as to how an interocitor functioned, or even what it was, yet judging from the list of parts and the accompanying diagrams, it was an enormously complex piece of equipment. Cal realized that even if he ordered a set of interocitor parts, and somehow succeeded in putting one together, he would have no way of knowing if it were operating properly or not. Was the entire catalogue some monstrous joke, of which he was the butt, or had Cal stumbled upon a technology vastly superior to our own? Cal had to know - his curiosity, both as a scientist and as a man, was aroused - and thus began Cal's apprenticeship with the Peace Engineers. And in the surprising events that followed, Cal Meacham became involved in an adventure to stagger the imagination. One of the truly memorable science fiction experiences of this or any other year, THIS ISLAND EARTH is that rare science fiction novel which combines a sense of social responsibility and thrilling action within the framework of a cosmic struggle to maintain a barrier against an incredible invasion. Here is a book that will appeal to everyone who has ever stopped on a starry night to gaze in wonder at the vastness of the universe, and to ponder the place in infinity of this island Earth.