_The Armies of Memory_ is the excellent final volume of the as far as I know unnamed series by author John Barnes that began with _A Million Open Doors_ and continued with _Earth Made of Glass_ and _The Merchant of Souls_.
The main character, as was the case with previous installments of the series, is Giraut Leones, native of the culture of Nou Occitan, publicly a famous musician though in reality a special agent for the Office of Special Projects (OSP), the military/intelligence/police arm of the Council of Humanity, the governing body of the Thousand Cultures, home to all known human worlds, located in a roughly hundred light year diameter sphere centered roughly on Earth.
Also as in previous installments, Giraut continues to advance the goals of the OSP, those being twofold. First, to manage the peaceful interaction of the myriad civilizations of the Thousand Cultures, some in conflict virtually since their founding, others in conflict since an event known as the Connect, when civilizations previously separated by many years of travel were suddenly united by the most momentous invention in human history since fire and writing, the springer (which as readers of the series will know, is a device that allows instantaneous travel between two points, no matter the distance, as long as both points have springers). Second, while managing diversity and conflict, keeping it under control and maintaining some sense of cohesion and unity between these various cultures, the OSP had to fight unity and stagnation in other cultures; seemingly the majority of the people in Earth's solar system (including Earth itself) had "gone into the box," had withdrawn from the world, become plugged into virtual reality nonstop, never leaving their apartments and sharing only the interstellar meta culture, utterly dependent upon aintellects (artificial intelligence in the form of robots and sentient computer programs) to run things. The first situation, if unchecked, would lead to the possible destruction of humanity in countless bloody wars and genocidal actions. The second situation, again if unchecked, would lead to the stagnation and extinction of humankind. Both situations would leave humanity woefully unprepared should it ever have to face a real threat from the stars.
_Armies of Memory_ opens with Giraut trying to record a new series of songs he called the Ix Cycle, named after Ix, a prominent figure readers of the series may remember from _Earth Made of Glass_. The songs were bold, original, and combined styles from widely different and even mutually opposed cultures, sure to generate comment at the very least and opposition at the very worst.
The reader also finds Giraut and his team members dodging assassination attempts. Who is trying to kill Giraut? Does someone violently oppose the Ix Cycle or are their other, quite different reasons?
Giraut and his team in the course of their recording the Ix Cycle and investigating the assassination attempts uncover a rather complex web of people and events. These threads include the existence of extraterritorial colonies beyond the frontiers of known human space (illegal colonies, not established with permission or even knowledge of the Council of Humanity), uncovering the reasons why contact was lost with one of the colony worlds of the Thousand Cultures decades ago, the fate of the builders of ruins found in human space (constructed by a very poorly known species labeled the Predecessors), the true nature of the wants and desires of the aintellects that in many ways really run human society, the whereabouts of a renegade OSP military unit called the Lost Legion, the real story behind the invention of the springer, and the existence of a long lost psypyx of Shan (Shan being the deceased former head of the OSP and a psypyx being a complete recording of a person's mind, sufficient to reconstruct that person inside a newly cloned host body). All of these diverse threads in the end do tie together though I have to admit that not all are completely resolved, despite this being presumably the last book in the series. Indeed, though Giraut's story does get a more or less definitive conclusion, to me it felt as if some story elements were just getting really interesting as the book ended, leaving me demanding further exploration of those ideas. I know it is a good thing for an author to leave its readers wanting more and I myself have tired of seemingly never ending novel series, leaving the reader weary of the story, tired of waiting, and less and less hopeful of any real conclusion of the series (not to mention tired of shelling out so much hard earned money), but this story certainly could have gone on for at least one more book and proved I think quite exciting.
I found the book very well written and quite engaging. My favorite part - I hope I am not giving away too much here - is a section detailing Shan's childhood from Shan's point of view, which I thought was fantastic writing and very gripping. I sincerely hope we have not seen the end of the series and I think the setting is quite rich and one open to a great deal of exploration. His alien worlds are believable, I find the idea of a created culture for each colony intriguing (and particularly liked how Barnes used some non-Western cultures), and liked what he had to say about overall trends of too much diversity and too much unity in society. I would also wouldn't mind seeing him put together some sort of guidebook to this setting, much like Peter F. Hamilton did with the setting of his _Night's Dawn Trilogy_ (the series that began with _Reality Dysfunction_).