Lowdown: A human clone goes after his "original" in order to save humanity.
A good sequel is hard to write, as Philip Pullman's The Subtle Knife had proved. Yet John Scalzi's sci-fi sequel to Old Man's War certainly qualifies as a good sequel, a sequel that certainly puts me in a position to want to read the third installment.
The Ghost Brigades is set in the same world as its former, but it focuses on new characters while reusing some of the supporting cast as Scalzi goes about explaining the world out to those that didn't read the prequel. The main differences are the absence of John Perry, the first book's hero, and the story that is no longer told through a first person's eyes. In making these changes, Scalzi manages to avoid abusing the old while still using it constructively; add to that his sarcastic writing and his lack of taking himself too seriously and you can see why this is a writer I like coming back to.
The story starts from the point in time Old Man's War had finished. We quickly (and very smartly) learn of a conspiracy by three extra terrestrial species to take on humanity together, and we learn they have on their hands a human traitor, a brilliant scientists that knows a military secret or two that could help crash humanity. So the human army fight this threat by creating a clone of the traitor scientist and fitting it with the traitor's recorded consciousness (made available to them through a rather cheap trick). That Frankenstein of a clone (an observation made by Scalzi throughout the book) has a consciousness of his own but also that of his original; trained by the human army's special forces, he goes on fighting missions under the command of Old Man's War Sagan character. As the clone's original consciousness slowly dawns on him, the question becomes which way he would turn: would it be the old or the new personality that calls the shots?
As with Old Man's War, The Ghost Brigades borrows a lot from former science fiction books. To his credit, Scalzi mentions those in the book itself (either as a part of the plot or in his closing notes). Yet Scalzi manages to create here a book that is slightly more than the parts he borrowed: it's a major page turner for a start, leaving me constantly wanting to know what happens next; it's got some very exciting battle scenes; and most importantly, it has an agenda of its own. Through the comparison between the traitor and his clone, Scalzi tells us a lot about what it is that makes us human; where it is that we are free to make our choices and where it is that we are only fooling ourselves when we consider ourselves free. His main message is very anti fatalistic one, and I'm totally with him there.
Yet The Ghost Brigades isn't perfect. It's a nice book, but it often feels like a typical American film: If someone finds something early on in the book, you know he's going to be using it later on; and the cuts between one scene to the other, always at the peak of the thrill, feels too unnatural after the hundredth time it's done (still exciting, though).
Overall: An exciting science fiction book that falls a bit short of true classics. 3.5 out of 5 stars.