This is book 5 in the Lieutenant Leary series. The story is pretty much self contained, but it only refers briefly to things in the recurring characters' backgrounds, rather than fully explaining them. Better to start at the beginning.
I finished this book a couple of days ago, and I find that enough of it didn't stick as it went whizzing by that I can't really explain it. It's fairly entertaining space opera, but there are some things that are getting tiresomely repetitive. I wouldn't go so far as to say the series has jumped the shark, but I think this is a weaker book than the earlier ones. 6 out of 10.
**** PLOT HIGHLIGHTS -- SPOILERS ****
This isn't a full plot summary, because a lot of the plot just passed over without leaving any tracks in my memory.
Leary returns, triumphant, from his last mission, only to discover that Admiral Anston has had a heart attack and his replacement wants to screw the people Anston favored, so instead of getting an assignment worthy of his abilities, Leary is assigned as a military advisor for a local dispute in the back of the beyond. He isn't even given a ship, but by using his own considerable wealth and a liberal interpretation of his orders, he puts his crew back together and takes the Sissie, nominally his private yacht. Nataniel Arruns, an ambitious younger son of the king of Pellegrino, has taken a force of 10,000, nominally mercenaries but really Pellegrino troops, to Dunbar's world, and Bennaria, which is in the same system as Dunbar's World, is threatened enough to call on its alliance with Cinnabar. Pellegrino controls trade through the area, and the rich merchants on Bennaria are trying to balance things so they don't upset their gravy train. He manages to ally with Corius, the less corrupt and more competent faction of the Bennarian leadership. Corius outmaneuvers Waddell, the really slimy leader of the Bennarian council, and takes his own private army to Dunbar's World. Leary manages to outmaneuver the Pellegrinan cruiser with a Bennarian destroyer he's taken over, crewed by the loyal retainers of Krychek, who had a ship of his own that he hasn't been able to get repaired due to the political mess on Dunbar's World. Thus, the invasion of Dunbar's World is foiled, the bad guys are kicked out of government on Bennaria, the Alliance plans at gaining influence in the region are in disarray, and Leary is the hero of it all. Tovera, Adele's sociopath bodyguard, has an affair with Corius' alien lizard-man bodyguard Fallert. Adele has a tremendous amount of angst over the people she kills, but still doesn't admit she loves Leary as more than a friend.