Two ecological engineers must change their world to save it. Eons ago, ecological engineers like Caleb and Fee designed their world. But even the best designs wear out eventually. Now, Arcadia is threatened with environmental collapse, and only the men and women of the Survey can save it. "Storms, floods, drought. Don't bother taking your pick," says the planet, "you're going to get the lot." When the Survey sends tree-loving Fee to help make a lake smack in the middle of Caleb's desert plains, he's less than thrilled. His family has deep ancestral and economic ties to their dusty land. If they knew what Caleb and Fee were doing, they'd run them out of town. So, the two must work in secret, altering entire landscapes before the locals find out and try to stop them. An impossible task, surely, when the only thing they have in common is a love for the very places they must change. But why Fee and Caleb, and what does the Survey truly plan for them?