Children of Janus

On the planet Janus, six iron-age tribes have formed an uneasy alliance against the perils that face them. In addition to the ferocious predators that roam the continent, bandit tribes search for loot, and dramatic changes of climate periodically force everyone to undertake long, perilous migrations to escape blizzards and drought.
When the signs point to the imminent onset of another climate change, trouble breaks out between two of the allied tribes, forcing Tarvos and a small group of friends to undertake a perilous quest to the other side of the continent. Can Tarvos rescue the beautiful Daphnis, kidnapped by bandits, and return to his tribe before his entire family and everyone he knows leaves to begin their five thousand mile migration north? And how will they react as they begin to uncover clues that point to the secret of Janus? The discovery that he and all his people are the unwitting accomplices to the greatest crime in the history of mankind?