Serpent Caravan

Earth is in a desperate battle against the alien Sinaquan and losing! The only hope is to send colonists to places the enemy isn't likely to look, marginal worlds, such as Viejo, with its migrant seas, and gas-giant neighbor, Prometheus. But when those colonists explore for a new base location, disaster strikes! The Sinaquan have found them. And their Serpent Caravan may have nowhere left to go...