The Iron Man is a fascinating cross-section of the works of Louis-Sébastien Mercier (1740-1814), a unique writer whose originality and enterprise has never yet been given the full credit that it deserves. From an early contribution to the development of the literary vampire to a pair of revealing philosophical spectacles, from a world that seems to be the best of all possible worlds to interplanetary voyages, and the eponymous "Iron Man," a precursor of superhero fiction, many of Mercier's visionary fantasies are still fresh and original today, his exploratory zest not having been weighed down by the burden of subsequent sophistication. We can best appreciate the full effect of the liberation that the device of dreaming gave to his literary imagination, turning him into a genuine precursor of surrealism who created a number of what were to become conventional tropes of supernatural fiction in original ways.