This is the second book in the Old Man's War universe. It is in the same universe as Old Man's War but does not follow tightly and should make sense on its own.
This is a fascinating universe. Scalzi continues to explore some truly intriguing ideas about the nature of consciousness, and also has some interesting stuff about a lot of other bits of being human, like trust and betrayal, a purpose in life, and how we connect with others. It's all in the context of an interesting and exciting story that mostly makes sense given the initial premises. There are a few things that seem Unfortunately, it winds to an ending that's not as pleasant as I might have hoped. It does do a good job of telling a complete story but still leaving me curious about what will be happening in the next book.
8 out of 10.
We start out with Cainen, a scientist, being attacked in his lab and taken prisoner. We don't realize at first that Cainen is an alien Rraey and he's being captured by humans. A Rraey military officer is supposed to kill Cainen to keep him from being captured, but Cainen doesn't cooperate. He then allows himself to be blackmailed into cooperating with his captors, because he's just not willing to die. The information he reveals, combined with other information the humans have, allow the realization that Charles Boutin, a genius of the first rank who had apparently killed himself recently, had actually faked his death and defected to aliens who intended to destroy the human race. Boutin left behind an electronic copy of his consciousness in an alien super computer, and the human generals decide to clone him and upload the copy into the clone. It doesn't work. Jared Dirac is born as a Special Forces soldier and goes through his regular training. He buys some black jelly beans, and this triggers a memory, first that they were his daughter's favorite, and then that his daughter is dead. He goes nuts for a bit but gets back in control. He goes on a mission where his squad kidnaps the Eneshan heir, blackmailing the Matriarch into quitting the alliance against the humans. Then Boutin is taken to the base where Boutin's daughter died. This triggers more memories. He now knows where Boutin is, or at least where he was gong when he escaped; inconveniently it is in the home system of the Obin, the most inscrutable of the alien alliance against them. His squad goes on a covert mission to grab Boutin. Most of them are killed when their brain implants, called BrainPals, are disabled, since all their tech is controlled through them. Jared is captured by Boutin and meets Zoe, the daughter, who wasn't really killed after all. The Obin lack consciousness and are willing to do anything to gain it; Boutin is a consciousness researcher and is convinced (and has convinced the Obin) that he can give it to them. He's also convinced himself that the human government, the Colonial Union, is evil and oppressing humanity, and that if it can be destroyed militarily, the humans who aren't killed in the war will be able to live in the galaxy. Jared doesn't buy this and isn't willing to carry the BrainPal computer virus that Boutin means to use to disable the human military, so Boutin is going to transfer his mind into Jared's body, killing him. The surviving members of his squad disable the BrainPal jammer and are making progress on taking out the base. Jared gets Sagan, his squad leader, to agree to rescue Zoe and trust that he will take care of Boutin. He accomplishes this by leaving behind a suicide program in his BrainPal. Boutin transfers himself into Jared's body, killing Jared, and then gets killed himself when Jared's body self destructs. Sagan now knows too much about the real situation in the galaxy, but the generals decide to keep her quiet by retiring her a little early to a new colony world where she won't be able to tell anyone, along with a boyfriend and Zoe whom she adopts. Before she leaves, Sagan helps Cainen kill himself, ending his own turmoil about having betrayed his own people.