Here's why:
* No book with that exact title: There's no widely known book titled "The Gun" by Paul Langan. It's possible it's a lesser-known work or an unpublished manuscript.
* Need more context: To find out the page count, we need more information, such as:
* The full title and publication details: Is it a novel, short story collection, or something else?
* The specific edition: Different editions of the same book can have varying page counts.
To help find the answer, please provide more details about the book you're looking for.