Far over the Edge, the Mother Storm is brewing—a storm more terrifying than any seen in the lifetime of any Edgelander. Sweeping in from the open sky, it must strike the source of the Edgewater River to bring new energy to the land. But in its way is Sanctaphrax, a magnificent city built on a floating rock and tethered to the land by a massive chain. Only one person can save the Edgelands from certain disaster: Twig, the young sky pirate captain who dared to sail over the Edge—and returned with his memory shattered and his crew flung far and wide. But to recover his memory and take action, Twig must first find his lost crew. And this means a journey back into the Deepwoods, and beyond.