I picked up a pile of Brunners at Gould's. As always, I walked in with hopes of finding some particular books, viz the ones that Mark suggested, and walked out with other things. This one takes on a classic theme, viz alien anthropology, ala Asimov's The Gods Themselves and Clarke's Rendezvous with Rama, and does nothing special to it. Oh, of course the boy genius solves the puzzle of why the aliens died out. Sorry to spoil it for you.
What I found most frustrating was the imprecision: apparently these aliens produced "exactly one" of their artefacts, or at least that is what was found by the 100,000 year late Earthlings. Only one knife? One house? Err, of course not, he mostly meant one type of knife, house, etc. except perhaps where he doesn't; maybe there is just one ship in the entire world. What was the point of that telescope anyway? I hoped it was going to go all 2001 and take great vengeance on the various stereotypes in this book.
The ending is a bit depressing (perhaps too like the subsequent Rama X for two many Xs) and a tad predictable given all the self-absorbed personalities involved. Are they not smart enough to think up other ways to pass their time?
This review is a bit fairer.