Spiral Arm series, #3. (My thoughts on the first two volumes here.)
An entertaining story of spies and intrigue, which you might think of as Tinker, Tailor, Soldier, Interplanetary Assassin.
In Flynn's universe, there are two rival interplanetary alliances, each with its own set of spies/security forces; think of each as a cross between the CIA and squads of Navy SEALs. The United League has the Hounds; the Confederation has the Shadows. This novel takes place among the Shadows, and follows the efforts of some to rebel against Those of Name, the mysterious figures who oversee them.
Series protagonist Donovan, the scarred man, was once a Shadow, and the rebels want him to join their cause, believing that he has knowledge which will aid them. But Donovan's scars are psychological as well as physical, and it's not clear whether he will be able to remember what they need; it's not entirely certain, in fact, that he's actually the man they think he is. And in any event, he wants nothing to do with the Shadows and their civil war.
As is often true with stories of this sort, there are a lot of characters, and loyalties and alliances are often unclear and shifting. Flynn makes it easy to keep track of everyone, though, in part though his delightfully memorable names; the language of his far-future universe has shreds of every culture and language from old Earth spread throughout it, giving us characters like Manluis Metataxis, Domino Tight, Ravn Olafsdottir, and Pendragon Jones. Certainly easier to remember those than it would be to keep track of Bob, Phil, Joan, and Dave.
Flynn wraps up the main story by the end of the novel, but Donovan's ultimate fate is left up in the air, and another volume will clearly be required to tie up those loose ends. It seems likely that the next volume will have larger roles for two characters who play relatively small parts in this one, the Hound Bridget ban and her daughter, the harper Mearana, and that will be a good thing. Looking forward to it already.