Followers of the evil elemental lord of air Hshurha have learned of the Pathfinder Society's plans to break open the Untouchable Opal and release Hshurha's ancient rival. One of Hshurha's lieutenants is gathering forces to deal a decisive blow to the Society and its new allies in the Concordance of Elements. If the PCs act quickly, they can make a daring strike, commandeering an airship on the Plane of Air and overtaking their enemy's fortress before it has the chance to rally its army.