The listing, The Green and the Grey has ended.
Timothy Zahn is a force in the sci-fi writing community, and this novel is a great example. Imagine if you will that two kinds of aliens are living among us in New York City. Now imagine what might happen when two ordinary humans, with issues of their own, stumble over this truth. And of course the Green and the Grey aren't getting along, so there is suspense and danger, too. It's just a really fun read. Hardback with dust cover. Slight water damage to one edge, but it's hardly noticeable. Non-smoking home. We need to downsize to move.