Free Soul of the Fire by Terry Goodkind

headwaters of the Dammar River gather, eventually to flow into the Drun River. These headwaters leach poisons from the ground of the highlands.
    “ The highlands are a bleak wasteland, with the occasional bleached bones of an animal that stayed too long and drank too much from the poison waters. It’s a windy, desolate, deadly place.”
    Zedd opened his arms to gesture, suggesting the grand scale. “The thousand tiny runnels and runoff brooks from all the surrounding mountain slopes collect into a broad, shallow, swampy lake before continuing on to the valley below. The paka plant grows there in great abundance, especially at the broad south end, from where the waters descend. The paka is able to not only tolerate the poison, but thrive on it. Only the caterpillar of a moth eats some of the leaves of the paka and spins its cocoon among the fleshy stems.
    “ Warfer birds nest at the head of the Nareef Valley, on the cliffs just below this poison highland lake. One of their favorite foods is the berries of the paka plant that grows not far above, and so they are one of the few animals to frequent the highlands. They don’t drink the water.”
    “ The berries aren’t poison, then?” Richard asked.
    “ No. In a wonder of Creation, the paka grows strong on the contaminates from the water, but the berries it produces don’t contain the poison, and the water that flows on down the mountain, filtered by all the paka, is pure and healthy.
    “ Also living in the highlands is the gambit moth. The way it flits about makes it irresistible to warfer birds, which otherwise eat mostly seeds and berries. Living where it does, it is preyed on by few animals other than warfer birds.
    “ Now, the paka plant, you see, can’t reproduce by itself. Perhaps because of the poisons in the water, its outer seed casing is hard as steel and will not open, so the plant inside can’t sprout.
    “ Only magic can accomplish the task.”
    Zedd’s eyes narrowed, his arms spread wide, and his fingers splayed with the spinning of the tale. Kahlan recalled her wide-eyed child wonder at hearing the story of the gambit moth for the first time while sitting on the knee of a wizard up in the Keep.
    “ The gambit moth has such magic, in the dust on its wings. When the warfer birds eat the moth, along with the berries of the paka, the magic dust from the moth works inside the birds to breach the husk of the tiny seeds. In their droppings, the warfer birds thus sow the paka seeds, and because of the singular magic of the gambit moth, the paka’s seeds can sprout.
    “ It is upon the paka, thus brought to leaf, that the gambit moth lays it eggs and where the new-hatched caterpillars eat and grow strong before they spin their cocoon to become gambit moths.”
    “ So,” Richard said, “if magic is ended, then … what are you saying? That even creatures such as a moth with magic would no longer have it, and so the paka plant would die out, and then the warfer bird would starve, and the gambit moth would in turn have no paka plant for its caterpillars to eat, so it would perish?
    “ Think,” the old wizard whispered, “what else would happen.”
    “ Well, for one thing, as the old paka plants died and no new ones grew, it would only seem logical that the water going into the Nareef Valley would become poisonous.”
    “ That’s right, my boy. The water would poison the animals below. The deer would die. The raccoons, the porcupines, the voles, the owls, the songbirds. And any animal that ate their carcasses: wolves, coyotes, vultures. All would die.” Zedd leaned forward, raising a finger. “Even the worms.”
    Richard nodded. “Much of the livestock raised in the valley could eventually be poisoned. Much of the cropland could become tainted by the waters of the Dammar. It would be a disaster for the people and animals living in the Nareef Valley.”
    “ Think of what would happen when the meat from that livestock was sold,” Ann coached,