An uneasy truce with the alien races continues, while the Earth forces investigate a ring of six black holes of clearly artificial origin.Meanwhile the civil war on Earth reaches its peak, and the USNA forces resort to a very unconventional plan to turn the tides of war.The unexpected discoveries continue , and universe starts looking darker and vaster than ever before.If you have read previous books of the series, you definitely need to read this one.If you haven't - read all the previous books, just to get to this one. Yes, it's worth it.Now, don't get me wrong - I am giving this book four stars. That means it's a good-to-great book, something that is really worth the time. Why not five stars, then? I reserve five stars for the books that have the timeless quality - Frank Herbert's "Dune", Dan Simmons' "Hyperion" etc.This is a military sci-fi series. It's not timeless, but it is hell of a good read.There are many things that make (or break) this kind of books - the series gets all of them right: interesting and changing plot, good writing and the future military technology that is plausible and thought-through. The characters are likeable and easy to relate to, but overall the character arcs are the only thing that I would mention as just average.What I expect from good SF, be it military or not, is a fresh idea, something that will keep me thinking after I finish the book.I think this book has it - without too many spoilers, author shows how alien can another race be, and how much our human ethics influence our reactions to something that is not wrong, but just of a different evolutionary origin.Author managed to construct the alien psychology and behavior of the alien race in detail, supporting every trait with the evolutionary background that made it plausible. While the initial reaction to the alien race one has is repulsion, it was a surprise to me to realize it was my own narrow-mindedness and being conditioned to human ethics that caused the reaction, and that there is no objective "right" or "wrong" in the universe, just evolution in its myriad forms.It is usual for the SF series to wither and get worse over the course of the series - but not this one.Read it, enjoy it and wait for more books from this brilliant author!