From the introduction:
Eberron is a world of intrigue and swashbuckling adventure, were industrialized magic has started to pull the civilized world out of the medieval technology level it has stagnated at. Lightning rails provide magical transport between countries, messages are passed around the world in an instant through the speaking stones of House Sivis, and even common goods are produced with exceptional quality and speed thanks to magewrights who work magic into their craft. Magical bloodlines form the basis of trading monopolies and thinking constructs now walk among the natural humanoid species. The continent of Khorvaire has only recently emerged from the century long conflict called the Last War, a succession crisis that split the kingdom of Galifar into several successor nations. The war would still be raging, if an unknown arcane accident (or attack) had not completely annihilated the country of Cyre in a single night, transforming it into a mist shrouded wasteland of mutants and wild magic now called the Mournland. Not knowing what (or who) was responsible, the warring nations laid down their arms, but few believe the peace will really last. Already intelligence agencies, mercantile Dragonmarked Houses, religious cults, and secret societies jockey for power, information, and resources that will give them an edge in this new age of peace or the next war that likely waits beyond it. All the while, dragons and fiends, ancient beyond measure, engage in their own intrigues and push agendas beyond mortal ken.