The Iron Pirate is the tale of a great gas-driven iron-clad, which could outpace the navies of the world and terrorize the Atlantic Ocean. Constructed of a phosphor-bronze alloy with engines in the vessel that burn hydrogen, manufactured by passing steam through hot coal to produce a mixture of hydrogen and carbon dioxide, the nameless ship is captained by the infamous Captain Black and it brings horror to every ship and every sailor that comes in its path.