The Difference Engine

In 1855, the world took a radically different historical path. The steam-driven Difference Engine designed by the British mathematician Charles Babbage was not only successfully built but also widely adopted, bringing the computer age forward by more than a century. Steam power and punch cards, gears and information flows interweave into a smoke-filled London where the Industrial Revolution and the Information Revolution converge, reshaping the global political, economic, and military landscape.

In this world, the poet Byron did not die in Greece but became the leader of the Industrial Radical Party and rose to the office of Prime Minister, using a vast intelligence network driven by the Difference Engine to scatter British agents across the globe and tear the United States apart. Marx and Engels founded a commune in New York, seeking to build a socialist America. France under Napoleon III, meanwhile, built a super-Difference Engine called "Napoleon the Great," eyeing Britain's supremacy with predatory intent.

At the true heart of the book's title is Ada, Byron's daughter. A female scientist hailed as the "Queen of the Difference Engine," she wrote a set of secret program cards concealing astonishing wealth and power, drawing multiple factions into the fog of London. Sybil, a woman fallen into prostitution; Mallory, a geologist; and Oliphant, an intelligence officer, are successively drawn into the contest over the code, while conflict among the Luddites, the Industrial Radical Party, and radical workers threatens to erupt at any moment. Structured in chapters named after "programs" and unfolding along multiple narrative threads, the novel interweaves suspense, political intrigue, and questions about the ethics of technology, together presenting a Victorian world ruled by steam and gears.