Toward the end of my books, I try to keep ratcheting up the tension, not giving the reader a place to jump off, where they can assume the protagonist will be okay until the next day. It's a fine line to walk. A writer can't just throw in cliffhanger after cliffhanger, because it will wear the reader down. Mix in a few teases with the cliffhangers, though, and you just might keep the reader going all night.
Here's the email:
"A pox on you, DE Johnson! Another school night up until 1:30am -- had to finish Det Breakdown -- and missed the Y this morning. If the Mr. mentions something about fat and lazy at least I can say I am well-read. OK, so now I am destitute. When will there be another? I want them to get married and somehow have children."
If my skin starts breaking out, I'll be worried. Otherwise I'll just enjoy the thought of another exhausted reader ...