- You may be looking for the anthology or the short story.
The Book of the Enemy was a book which erased its readers from history, turning them into fictional characters. Sherlock Holmes heard many rumours of the Book during his investigations, coming to the conclusion that its purpose was to shape the Spiral Politic to be as the Enemy wanted it.
In the 1910s, the Book was kept in the library of the British Museum. (PROSE: The Book of the Enemy)