Zoe's Tale is set in the Old Man's War universe -- the universe established in his debut novel -- in which the human race has begun to colonize the stars, creating a secretive military bureaucracy that oversees it all. The shock troops of the colonization effort are genetically modified supermen who started out as senior citizens on the overcrowded Earth before opting to get a new finely tuned body and a new lease on life battling the alien races that compete with human beings for access to the plum planets that can sustain life.
The Lost Colony, the third Old Man's War book, tells the story of the Roanoke colony, the first colony made up of colonists from other worlds (instead of Earth) that single-handedly stands off a fleet of 400 alien races that are determined to wipe the colony out.
In Zoe's Tale, we have the same story, told from the point of view of a different character, Zoe Boutin Perry, the adopted teenage daughter of the colony leaders (themselves ex-military supersoldiers from the previous volumes). Zoe is incredibly likable, believable, and witty -- a smartass's smartass. She also has a unique position in interstellar politics: her birth father, Charles Boutin, created a technology that gives consciousness to a powerful alien race called the Obin. The Obin had been uplifted into intelligence by a race of cruel and godlike aliens who endowed them with intelligence but not consciousness. The Obin revere Zoe as a goddess and her safety and disposition are the matter of a complex treaty between humanity and the Obin.
Zoe is a colonist on the sleepy backwater world of Huckleberry when her parents are tapped to lead the experimental Roanoke colony, a move she wholeheartedly supports. On the colony ship, she makes a group of fast friends and emerges as a leader herself, something that is doubly important once the ship arrives and it transpires that Roanoke isn't what they were promised. Instead, the new colony is a pawn in a galaxy-spanning military game that endangers all the colonists and exposes them to hardship.
As the story plays out, Zoe blossoms beyond her outer shell of witty barbs and finds hidden reservoirs of strength and maturity. On her journey, she is forced to confront the inequity of her relationship to the Obin, and to question the nature of intelligence and consciousness.
This is a novel for young people that has it all: action and adventure, science and philosophy, love and angst. Scalzi's own likable personality (and that of his delightful daughter, Athena) shines through the narration, making these people into just the sort of folks you'd like to be stranded on a hostile planet with.