Thirteen-year-old Twig, having always looked and felt different from his woodtroll family, learns that he is adopted and travels out of his Deepwoods home to find the place where he belongs. Young Twig lives in the Deepwoods, among the Woodtrolls, but he isn't one of them. In a brave attempt to find out where he belongs, Twig wanders into the mysterious, dangerous world beyond the deepwoods. He meets a collection of odd companions, such as his wise...

In his continuing adventures, Twig, now sixteen years old, joins the crew of his father's sky pirate ship and embarks on a dangerous mission to collect the powerful stromphrax, a substance that purifies water and also prevents the city of Sanctaphrax from floating away.