Neo-Earth

The voyage: a ship the size of a country, bound for a new world that may be humanity's last chance to survive. She is built as a long spine strung with vast turning drums, each one a town of decks and weather-machines and recycled air, and she carries more souls than any home should hold, falling through the dark toward a place no one aboard has ever seen. The crossing takes most of a lifetime, long enough that a whole generation is born along the way who will only ever know the ship. This is where Khaedin's thread begins.