They Hide, We Seek
1990: Isaac's Universe 1: The Diplomacy Guild, Avon Mass market paperback, 260 pp.
2002: In Another Country and Other Short Novels, , 311 pp.
Isaac Asimov invented the setting for this story and the others in the shared universe called Isaac's Universe . There are six spacefaring species in the galaxy, and each one of them has very different requirements in a planet: humans like oxygen-rich worlds of a certain gravity; the insectoid Locrians prefer neon and low oxygen content; the winged Crotonites like a thick atmosphere poisonous to humans; and so on. This situation leads to an uneasy peace between the species. Silverberg's story concerns Captain Hayn Wing-Marra of the research vessel Achilles, who stumbles into a very unusual situation: a colony of Crotonites on a barren, airless moon which should be of no interest to them at all. What he and his crew discover there will change the balance between the Six Races forever. The rest of the stories in this book (by David Brin, Robert Sheckley, Poul Anderson, and Harry Turtledove) and the other books of the series concern (in varying degrees) the aftermath of this discovery. It really is a fascinating universe, full of interesting possibilities.
The story, interesting as it is in context, does not work so well when isolated from its original setting, and does not have a solid ending, since it was written specifically as a beginning.
Martin Greenberg edited three books in the Isaac's Universe saga:
The Diplomacy Guild
Phases in Chaos
Unnatural Diplomacy
There are also two novels set in the same universe:
Fossil by Hal Clement
Murder at the Galactic Writers' Society by Janet Asimov