I didn't realize that Cook had written any science fiction until Chad Orzel gave this long out of print book a glowing recommendation at a Boskone panel on space opera. I'm a huge fan of Cook's Garrett series of fantasy detective novels, and I knew about his other fantasy stuff, but his SF stuff was new to me. (I notice that in my notes from Boskone, it was mentioned in another panel that Cook is an example of a guy who writes very good SF, but writes far more fantasy, because apparently that's what his fans will buy. Kind of an interesting trap.)
Cook doesn't make it easy on the reader. There are four, maybe five, factions, unexplained historical references and technology, and more stars with names like V.Rothica and P.Jaksonica than Tolkein had elves. The setting is a human dominated interstellar empire called Canon Space run by family owned trading Houses. The peace is kept by the Guardships, huge, autonomous starships that patrol the Web, a system of pathways connecting the stars that allow interstellar travel. The Guardships are similar in purpose to Gort in The Day the Earth Stood Still, and are equally ruthless in enforcing the law.
The basic plot is that one of the Houses is trying to wrest control of the web from the Guardships while they are distracted by an invasion (instigated by the House) from the Outside. One Guardship, VII Gemina, catches a hint of the plot, and starts investigating. As the story develops, alliances change both among and within the factions, and there's all sorts of skullduggery going on. It's a hard universe to get comfortable in, because every time you start to think thay maybe you've finally got things sussed out, things change.
Yet for all the space opera, this is also a book about identity, and what happens to it in a universe where humans can be bioengineered and cloned whilst their personalities are recorded to be reused or stored. Jo Klass, the soldier on VII Gemina who is one of the main protagonists, was born several thousand years prior to the events in the book. That's partly because she spent most of that time in cold sleep, waiting for a call to arms, but it's also because whenever she was killed in the line of duty, the ship created a clone, and imprinted it with the most recent recording of her personality. Her memories have gaps because of this, as do others on the ship. At one point, she takes a lover who is later killed, and when he is resurrected, he has no memory of that part of his life.
A Guardship's crew can also achieve immortality of a sort through deification, where certain leaders have their personalities stored in the ships computer as AI's, much like the bottled heads in Futurama. Meanwhile, each Guardship is itself an AI, capable of fighting the ship on its own, much like the Andromeda Ascendant. The consequence of this is that over time, each Guardship has its own way of dealing with the universe and its crew. Some have gone varying degrees of insane, and have either killed their crews, or scared them off the ship. Some have created avatars that roam the corridors. The AI's are recorded, too, so that if a Guardship is destroyed, it can be recreated AI, crew (if applicable), and all.
Meanwhile, the Houses have their own take of cloning. Cloning to extend life is frowned upon, especially by heirs, but many of those in power have created multiple clones to act as surrogates and decoys. It leads to a shell game of sorts sometimes as the characters (and the reader) try to figure out who's actually who, and I haven't even mentioned the aliens yet.
It's a difficult ride, but once it got going I enjoyed it quite a bit. There's enough here for two novels (and according to what Cook told Orzel, it almost was), and the ending isn't quite as satisfying as one might like, but it's well worth the effort if you can find a copy.