Between Silk and Cyanide: A Codemaker's War 1941-1945 is a book by former Special Operations Executive (SOE) cryptographer Leo Marks, describing his work during the Second World War. It was published in 1998 by HarperCollins. Marks' interest in cryptography dated from reading Poe's The Gold-Bug as a child. His father Benjamin was a partner in the book shop, Marks & Co at 84 Charing Cross Road. As a boy, Leo had begun his code-breaking with that used by his father, in noting the prices in his second-hand books.