...is Poseida, several light years away from Earth and the only other planet known to harbor intelligence at a time when Earth has made contact with it. It is also the place young Bill Hudson, a recent graduate in space medicine, wants most to visit. Though through a war scare, he is almost prevented from going, Bill's sojourn on the planet provides the means for stopping a war between Earth and Poseida when it is discovered that a traitorous Earth man, rather than the Poseidans, is responsible for the tension. Plenty of imaginings here for the fans but basically the book is a thinly veiled vehicle for thickly expressed political morality.