Book Four in The Airship Adventure Chronicles - Belle and Rett's adventures are not over. While Rett is involved in rebuilding the destruction caused by Dr. Krakov in the capitol city, the queen calls on Belle for a vital mission. She sails off to Icelandia to negotiate a treaty with the eastern countries, only to find the queen of that frigid land is hiding a secret that threatens to derail the vital progress of peace. Rett unwittingly uncovers a threat beneath Aereopolis, more dangerous than the attack of the mad scientist. This discovery sets off a chain of events that unleashes a century-old menace. Once again, Belle and Rett must count on resourcefulness, courage, and old friends to escape peril and save the day.