Devon's work takes him into the skies of New Earth and the great floating city of New Caelum.

Here, a new energy project is exploited by alien powers, and a terrible catastrophe looms. Helped once again by the Doctor, Devon calls on the Bird People of Nest City, as well as the great Solar Bears on their Ice Clouds to stop disaster.

But can the people of the skies put aside their rivalries long enough to make a difference?