> For the complete documentation index, see [llms.txt](https://cybersleuth.gitbook.io/cybersleuth/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cybersleuth.gitbook.io/cybersleuth/day-2/case-3-reading-about-the-book-cipher.md). # Case 3: Reading About the Book Cipher We've intercepted so many encoded messages in Book Cipher, we need our own decoder tool to figure out what these messages actually say. Can you code a solution for us? ### Tools to Use: * [ ] Python ## Activity *The Book Cipher takes a passage of text and uses numbers for the specific paragraph, sentence, and word to identify entire words. For example, a word we're looking for could be located at paragraph 2, sentence 3, word 8. We've provided you with a passage located in "book.txt".* ***Try this with a partner:** Create your own secret message in book cipher, and ask someone else to decode it!* Decode this: `(1, 5, 31)` `(1, 9, 40)` `(1, 1, 6)` `(7, 4, 16)` {% embed url="" %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://cybersleuth.gitbook.io/cybersleuth/day-2/case-3-reading-about-the-book-cipher.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.