This book collects two different stories from a series by David Weber and Steve White. It is the future, and humanity has made peace with their last foes, the felinoid Rigellians. There has been enough time for the races to grow friendly with one another, but then foes attack, forcing the two nations to join together and fight it.
Crusade, the first book, tells of a threat that arises out of a Warp Point known as Charon's Ferry. Nothing and no one has come out of Charon's Ferry since a force of crazed Rigellians chased a human colonization group into it during the war. But when a group of ships transit out of the Warp point, the humans hope that it could be the survivors of just such a colonization party. When they send a fleet to meet the newcomers for a peaceful parley, the other ships open fire, killing the entire task force sent to greet them.
The Rigellians are upset by this, as some of the ships slaughtered were theirs. So, in accordance with their rules of honor, since the attackers might be Terrans, they tell the humans that they must fight this war on their own, unless they also want renewed hostilities with the Rigellians. The humans have no choice but to agree, since they cannot fight a war on two fronts.
Problems confront the humans on many fronts. The ships that were wiped out were about a third of their navy, leaving them understrength. Elements in their own government are undecided as to whether to try and make peace with the attackers, completely extirpate them, or try to persuade them that their brethren made peace with the Orions, and they should as well. Also, that the enemy has been able to capture their tech, and can reverse-engineer and use their own weapons against them.
Also, some of the colonies want to come to some kind of terms with the attackers rather than go out of their way to fight them. But the President of Human Space puts an ex-President and war hero in charge of War Production, and human men and women come together to fight the invaders.
But as the fight grinds towards its inevitable conclusion, the question becomes not "Will they be dealt with?", but "How?" Can a society formed around the concept of a holy war ever accept that it and its leaders were so very wrong about what they believed? Or will they choose to live and die, in hatred and ignorance?
The second story, "In Death Ground", takes place many years after the first book. The heroes of the first war are confronted with a new foe, The Bugs, as they become known- an utterly ruthless foe who thinks nothing of sacrificing massive numbers of its own troops to grind whatever peoples and civilizations lie before it.
Humanity and its allies have a technological advantage at first, but even as the war goes on for months and years, that technological advantage is slowly whittled away by their foes, even as their troops and ships are ground away by the relentless attacks of the spider-like aliens.
Hatred for the Bugs runs high when the Human-Rigellian alliance manages to re-take one of their own captured colonies and see that the Bugs have been using the captive humans as a food source, and that barely any are left alive. When they take a world that the Bugs have been using for generations, the people there are more like cattle than humanoids.
And yet the war continues to grind on. The humans and their allies know they must exterminate the Bugs, but can they? Or will they simply be pushed beyond their own endurance? Can the Human alliance ever survive a war with such an inscrutable, implacable foe?
I have long loved David Weber's Honor Harrington novels, and this seemed to me to be like a great deal more of the same. And I did enjoy the first book. Unfortunately, by the middle of the second, it was all too much for me. It got to be a struggle to wade through the second story, and I was very upset at the end that the story didn't end. The book ends at a natural stopping point, but to find the end of the story of the war against the bugs, you'd have to find the third book in the series.
There can be too much of a good thing, and I do think the second story would have been more interesting to me had I been able to read them as separate books, and go away and read something else, something different, in the middle. Especially when the second book was (or seemed) so much longer that the first.
Unlike the Honor Harrington books, though, this series has no real "main" characters. Officers and people come and go. The heroes of the first book do not survive the second, and the chapter in which this occurs is used to drive home the point of how ruthless the "bugs" are and how the humans and their allies are completely unprepared to fight the bugs. As the chapter heading puts it "Even Heroes Die".
And fighting the war, both of them, take fairly severe tolls on the characters who are doing the fighting. One of the early commanders nearly goes insane from the psychological stress of losing so many of her troops in battle. While others are not so psychologically fragile, the war grinds down both bodies and souls equally. Being a hero is definitely not all fun and games, and the books make this point in spades. There's a reason why "May you live in interesting times!" is a Chinese curse.
War fiction buffs and fans of David Weber will enjoy these books, but it's a good idea to put it down in the middle and read something else to refresh your brain, as it were, and also to have the third book in the series ready if you do read it, as the cliffhanger ending is a rather major downer. Recommended.