As the Isle of the Four Kingdoms series continues in "Book Four - Firestorm", isle inhabitants are caught in the aftermath of the eruption of Half Moon mountain in the Kingdom of Four Peaks. An ashy-haze blankets most of the isle and threatens the isle's basic needs - shelter, fresh water, and food supplies. The Dragon Alliance team has just celebrated the scheduled wedding of two members of the team, as well as the unscheduled nuptials. Caught up in the joy of the moment, they are unaware of turmoil brewing around them that will blur their focus on the isle's survival:
* a distraught princess, who in seeking escape from her shattered dreams, falls prey to the twisted plans of a disgruntled sorceress. In seeking justice, this sorceress has unwittingly become a disciple to a long-forgotten, banished, 'gifting' spirit who wishes to rebuild its House and influence.
* the test of the newly-formed Dragon Council to gain acknowledgement by both man and dragons as the authority and governing voice of the isle's dragons in order to ensure peace.
* the possibility that some renegade dragons, including the renegade dragon leader, who were thought to have perished in the volcanic eruption, are very much alive and seeking to rally their cause. Will there be a confrontation?
Meanwhile, looming on the Isle of Oceanedge is possible future turmoil for the princess/sorceress. Her former foe and companion are guests of the prince of Oceanedge with whom they fled the Isle of the Four Kingdoms. They quickly learn that the lineage of Oceanedge's queen contains skeletons - secrets which open untold possibilities, including one which could lead to another showdown for the former foes.