Bantam, Jan 2008, $6.99
The colony ship was traveling through space for hundreds of years when explosions almost destroyed it. They traveled to the nearest planet in hopes of making repairs, but too much damage was sustained to too many systems. To make the situation even direr, the sun they orbit is starting to go supernova. Five centuries later, the artificial intelligence that enabled the captain to guide the people into safety splinters into fragments called angels, each with a different propose.
The crew from the ship has become the Exalts, near immortals with a symbiotic life form inside them that grants them superior powers. The Mean are normal people who have become a servant class. Rien, raised as a Mean, rescues the Exalt Sir Perceval only to learn she is her sister. Perceval transfers some of her symbiote into Rien. They trek to Engine hoping to prevent a war between Engine and the House of Rule as these sisters are the only hope left if this world is to survive.
The Exalts still live on the ship believing that it still can be fixed. The Angels have distinct personalities as each gained a segment of the AI. Rien and Perceval know they must stop a war that seems inevitable; to do so they must understand the various Angelic personalities, find a competent captain, and learn a way to survive the supernova. Elizabeth Bear creates a world filled with vast characters that in spite of the science fiction origins of its people seems believable. That is the essence of the Great bear universe.