Morne's youngest prince has gone missing somewhere in the Els...and Tess Mollyhawk, the daughter of the world's most famous pirate, is determined to find him. But she has her work cut out for her: the thousand islands of the Els are surrounded by some of the most dangerous seas in the world, full of pirates, sea serpents, and feuding colonial powers, constantly at war with one another. And the Chemical Revolution, which led to the creation of brassfire bombs and gigantic chemical cannons, has made these wars deadlier than ever.

Luc d'Fensi is searching for someone as well -- he's hot on the trail of a kidnapped Eleutrinian princess. But this kidnapping isn't quite what it seems, and before long Luc finds himself at the center of a conspiracy which could trigger a second -- and even more explosive -- Chemical Revolution.

And then there's Gerard Halfmark -- a disgraced Pistoleer who wants nothing to do with these intrigues. When his village is attacked by pirates, however, he's forced to pick up his pistol once again. For their captain has found a way to combine modern chemistry with long-forgotten sorceries, and may be on the verge of resurrecting mankind's most ancient adversary. If Gerard, Luc, and Tess can't find a way to stop him, his massive fleet could become as brassfire, burning everything it touches, and reduce all the world to ash.