The Difference Engine is an alternate history science fiction novel written in 1990 by Terry Pratchett and William Gibson. In this book, the authors present a parallel world where the differential analytical engine was developed in the 19th century, which is much earlier than our time. The events take place in 1855 in London, where technological progress actually allowed the creation of mechanical computers. The protagonist, Charles Baddock, is sent to investigate a mysterious murder and finds himself at the heart of political intrigue and technological developments. The book The Differential Engine combines the historical context of Great Britain at the time with elements of science fiction and mystical mysteries, creating a fascinating read for lovers of both history and fiction.