When the government forms an expedition to map the Far West, Eff has the opportunity to travel farther than anyone in the world. With twin Lan, William, Professor Torgeson, Wash, and Professor Ochiba, she finds that nothing on the wild frontier is as they expected. There are strange findings in their research, a long prairie winter spent in too-close quarters, and more new species, magical and otherwise, dangerous and benign, than they ever expected to find. When spring comes, the explorers realize how tenuous life near the Great Barrier Spell must stop a magical flood in a hurry. Eff's unique way of viewing magic has saved the settlers time and again, now all of Columbia is at risk.