It's possible you are thinking of:
* A different book: There are numerous books with "Room 13" in the title, but they often deal with horror or suspense themes unrelated to Dracula.
* A film or TV show: There have been various films and TV shows with titles like "Room 13" or featuring a "Room 13" element, but again, these are usually separate from Dracula.
* A misconception: Perhaps you heard a rumor or piece of information incorrectly linked to Dracula and Whitby.
If you can provide more details about the specific book you are referring to, I can assist you further.