The Colonial Defense Forces (CDF) learn that one of their top consciousness transfer scientists, Charles Boutin, has turned traitor and sparked an unprecedented alliance between three other species to wipe out humanity.
While investigating Boutin's clumsy attempt to fake his own death, the CDF discovers that Boutin had successfully stored a copy of his consciousness in a computer. The colonial Special Forces, nicknamed "The Ghost Brigades," create a CDF soldier body with Boutin's DNA to try to implant the copy of Boutin's consciousness into the new brain, to learn where Boutin has escaped to and what his intentions really are. The attempt fails, so the soldier becomes a private in the Special Forces, is given the name Jared Dirac and is assigned to a platoon commanded by Jane Sagan.
In the off-chance that Boutin's consciousness does emerge, Sagan and her superiors are determined to keep an eye on Jared. It does emerge, so Jared has to deal with memories of a life he hasn't lived, while trying to find out who he really is himself. When the extent of Boutin's treachery becomes known, it's clear there will be some difficult choices required to stop Boutin's alliance with the Rraey, Eneshan and Obin. After a firefight with the CDF special forces killing Boutin, it is discovered that Boutin has a daughter named Zoe.
John Perry and Jane Sagan decide to adopt her, and the Obin sign a treaty with the CDF that ends hostilities but leaves two protectors with Zoe to give thanks to Boutin, via his daughter, for giving the Obin consciousnesses.