Who holds the seeds to save a sky-high world? Arborium is at risk, the sharpened blades of rival Maw poised to saw off its bark and branches. What can a poor plumber's apprentice armed with little more than a monkey wrench do to stop the chopping? Carved into a massive, mile-high canopy, the forest kingdom of Arborium stands upon the tallest of trees. Within them, 14-year-old Ark holds the lowest of jobs: unclogging toilets. He's already up to his elbows in gunk when he really steps in it. He overhears a plot echoing through the pipes: Maw, a ruthless glass-and-steel superpower, is scheming to wield its axes of evil to strip Arborium of its wood - a natural resource now more precious than gold. The fate of a kingdom in the filthy hands of a plumber boy? Plunged into danger, Ark must make the treacherous climb down to the darkest roots of Ravenwood if there's any hope of rescuing his threatened tree home!