Do they all keep copies?
Dear Ms. Ivonna Wright,
I read with great interest your submission to my literary agency, titled "A Brutal Eunuch's Guide to Scrubbing." I must admit, you had me hooked the moment I saw that it was written in crayon. Your thirty-three page manuscript combines the brilliance of a young Marcus Paulk with the creative writing of Pierre Deligne, and will surely be devoured by archaean readers everywhere you send it.
Unfortunately, it suffers from one significant drawback: it's just too good. Merely looking at it enervated me to the point that I couldn't leave my seat. I daresay that should this book be published, you'll have trucks barrelling through the thick snows of Gehenna just to make deliveries on time. We'll have a single-book industry, and then what? I'll have to leave my job to be a menial hand in the new peccary feather trade.
No, it's best that you give me time to get the world ready for your work. For now, get a nice lead box and put all copies of your novel in it. Add some lye to protect it from insects, and bury it in the woods to keep it safe. Deep, deep underground.