After risking their lives to renovate Upside-Down Castle, Tonkachi and Renga set off for Buildon Garden to pursue the license granted to only the best carpenters in the land! When they find themselves standing shoulder to shoulder with Buildon’s top up-and-comers, it doesn’t take long for the nerves to kick in. It only gets worse when the proctor for the Buildon exam turns out to be none other than Smith, a master of fort construction. And what he has in store for round one has even his fully licensed colleagues shaking in their boots…