The Difference Engine, co-authored by William Gibson and Bruce Sterling, is an alternative history mystery that envisions a world where Charles Babbage's Analytical Engine was successfully built in the 19th century, leading to the early development of computer technology. The story follows Sybil Gerard, a young woman caught up in a conspiracy involving a mysterious set of punched cards. Gibson and Sterling's collaboration brings together elements of steampunk, mystery, and alternative history, making The Difference Engine a unique and captivating read.