Join Will deep in the cavern hollowed out by a madman plotting to control minds. Far beneath the earth, the air loom pumps out gas capable of hypnotizing the citizens of entire cities, bending all to one man's will.
When Will, José, and Finn discovered the airship Cloud Queen in an old mine in Southern California, they finally had a way to fight the burning and pillaging of the Freebooters, but they never dreamed that the specter of mind control stalking the land would take them east to the Rocky Mountains.
From infiltrating the Supreme Navarch's underground compound to fighting vicious airship battles in the sky, Will is pitted against the megalomaniac who desires to descend from the clouds in his Celestial City and transform the citizens of the world into his puppets.