First edition. Light shelfwear to edges and boards. DJ not clipped and covered with mylar. Pages tight and clean. Library discard with usual attachments/marks. 224 pages. HardCover Binding. Year: 1962. ISBN: 0. By the middle of the Twenty-Second Century, men had become star-rovers, maintaining friendly relations with many alien races among the galaxies. And Earth Administration co-operated with other advanced races in keeping a friendly eye upon the cultures of ""backward"" planets. The agreed-upon code was that science and gadgets beyond the cultural level of the peoples inhabiting such a planet would not be introduced by Earthmen, or other visitors.