Two and a half millennia ago, the artifact appeared in a remote corner of space, beside a trillion-year-old dying sun from a different universe. It was a perfect black-body sphere, and it did nothing. Then it disappeared.
Now it is back.
"Banks is a phenomenon ... wildly successful, fearlessly creative" William Gibson
"Thrilling, affecting and comic ... probably the finest science fiction he has written to date" New Scientist
"Banks has rewritten the libretto for the whole space-opera genre" The Times