The Difference Engine is an alternate history novel by William Gibson and Bruce Sterling. It is a prime example of the steampunk sub-genre; It posits a Victorian Britain in which great technological and social change has occurred after entrepreneurial inventor Charles Babbage succeeded in his ambition to build a mechanical computer called Engines. The fierce summer heat and pollution have driven the ruling class out of London and the resulting anarchy allows technology-hating Luddites to challenge the intellectual elite. A set of perforated punch cards come into the hands of the daughter of an executed Luddite leader who sets out to keep them safe and discover what secrets they contain.
