Four years after Napoleon's victory at Waterloo, Sir James LeRoque aims to sail to the heart of the world's troubles in search of a friend whose scientific expedition has vanished. But a manpower shortage in Britain forces LeRoque to crew his second-hand ship with women and hire a condemned pirate as sailing master.

The Bar Jack sets off for the Gulf of Mexico and the dangerous waters of El Radio, a forbidden zone around a giant volcano known as Volcan Rojo, the presumed source of mysterious events around the globe.

It's a changed world and LeRoque must navigate its perils - pirates, monsters, storms, strange powers, and his own shortcomings - in this gripping adventure from the author of Delivered to the Ground.