A crew of asteroid miners are ordered to investigate a self propelled moon and are whisked far, far away.
Most of the story is about the personal rivalries between factions of the crew, but there are generous helpings of hard-SF sense-of-wonder too. Some wonderfully disgusting aliens make a cameo appearance near the end.
This was a quick read. Like most of Reynold’s books, it’s not really a very good book by literary standards, but there are lots of nice ideas and images in it.