I read this book about 5-Feb-2014. I've read this book before. The book is copyright 1993. This note was last modified Thursday, 20-Mar-2014 18:43:53 PDT.
This note contains spoilers for the book.
It's 30 years after Mote. The Moties are still bottled up, the Blaine Institute that was founded at New Caledonia has moved to Sparta, the have Blaines resigned from the commission controlling contact with the Moties and had children (raised in company with the Motie mediators brought back in the first book), Ben Fowler is dead, and Kevin Renner is still Horace Bury's personal pilot (and handler for Navy security).
Kevin gets mugged on Maxroy's Purchase, by people not quite good enough (but they're all killed by Bury's security, nobody left to question). It's apparently a failed kidnap attempt.
Kevin has just discovered that people there are using "the gripping hand" routinely in conversation, and suspects this may be a sign of Motie leakage past the blockade. Bury has been terrified of this for 30 years—his deal is that he isn't hanged for his part in the New Chicago revolt, and spends his time working against human Outies, to free the Navy to maintain the blockade against the Moties. This may mean it's failed already.
But it doesn't; turns out it means that the newly-elected planetary governor was a crewman on the Mote mission, brought back some of these phrases, and is enough of a tri-d star that they've become locally popular (Jackson, sent down to Mote Prime but returned after a few days when it becomes clear that the Motie engineers will handle everything the party needs.).
Meanwhile, there are strange cash flows (Bury's specialty), and a mysterious substance called "opal meerschaum" that comes from uncertain places. Kevin pursues that, and hunts a "snow ghost" which seems to come from the same area, and it all comes down to nothing, from a Naval Intelligence point of view. The opal meerschaum is being brought in from New Utah, another Mormon planet outside the Empire which needs significant supplements to survive, via an oscillating Alderson point (sometimes it exists, sometimes not, on about a 20-year cycle, due to changes in the stellar environment). Jackson is going to find a way to bring New Utah voluntarily into the Empire fairly soon (it's clearly in their interests), and nothing of major security significance is going on. (Maxroy's Purchase is where Outies takes off from, and very interestingly indeed.)
However, that oscillating Alderson point is key. Turns out Buckman's motie (or his master) thought to feed the Empire false information on the curdle forming in the Coal Sack. When it condenses enough to ignite, it will change the jump points, including quite possibly creating new ones into (and out of) the Mote system. A grad student has published a new paper based on additional info getting a much sooner ignition date than the moties worked out with Buckman.
So we end up in the Mote system, with Keven Renner and a newswoman and Bury and his staff and Kevin Christian Blaine (older child, Naval lieutenant) on Bury's Sinbad, with an added Langston field. And it turns out that Sinbad is, um, nuclear armed. Up into the 50 megaton range. Dozens of them. Kevin hadn't known, I have the clear impression the Empire would not approve. Also Glenda Ruth Blaine and an aristocratic boyfriend on his racing yacht (that he's taken real championships with; it's so good the Motie engineers use his engines, tuned up a bit, rather than their own later on).
So, plenty of action, views of the Motie asteroid civilization, and a surprising amount of goodness. Much better than I remember.