Summary: Eff is an unlucky thirteenth child…but also the seventh daughter in her family. Her twin brother, Lan, is a powerful double seventh son. Her life at the edge of the Great Barrier Spell is different from anyone else’s that she knows. When the government forms an expedition to map the Far West, Eff has the opportunity to travel farther than anyone in the world, but nothing on the wild frontier is as they expected. The explorers find out how tenuous life near the Great Barrier Spell may be if they don’t find a way to stop a magical flood in a hurry. Eff’s unique way of viewing magic has saved the settlers time and again, but this time all of Columbia is at stake if she should fail.