The year is 1650. Humans have discovered Gravitae — the essence that grounds and binds things to earth itself. Combustion of Gravitae in shipborne engines has enabled massive naval vessels to take to the skies, nimble as birds. The rich and powerful have levitated the most fertile lands out of reach of ordinary people, building floating towns saturated with luxury. Driving this change is the globe-spanning Dynamic India Company, whose two heads are plotting to create an entire new world in the heavens by combining the stolen riches of the earth and the mass of the moon. Unstopped, this will spell certain disaster for everyone left on earth. It is not too late yet.