Young hero Twig is now reunited with his sky-pirate father as the lowliest crew-member of the flying sailship Stormchaser. In the fanciful physics operating at the edge of the world some stones can defy gravity, like the flight-rock that lifts Stormchaser. Thus the academic community of Sanctaphrax is built on a floating mountain chained to the ground of Undertown below.

Thanks to a tortuous history of corruption in high places the demand for chain-manufacture is forever increasing, leading to massive industrial pollution--because Sanctaphrax's precious, magically superheavy "stormphrax" ballast is gradually being stolen for alchemical use, and Stormchaser undertakes the dangerous mission to find new supplies at the deadly core of a Great Storm. But nothing, absolutely nothing, works out as expected in this madly twisting plot.

Twig's companions are beset by spies, traitors, memorable villains and the living dead and there are perhaps more deaths than might be expected in a "children's" novel, but Stewart's compulsive storytelling, perfectly complemented by Riddell's fine-lined illustrations, makes it all goodstuff. --David Langford