Blue Angel: A Novel by Francine Prose:
Dazed, they slouch out of the room. Swenson thinks of a story he heard when he first came to Euston, a cautionary tale about a teaching fellow who started coming into class drunk, scheduling her student conferences for midnight at a Mexican restaurant in Winooskie. Her students were so frustrated that at last, when she passed out in class, they put a paper bag over her head on their way out of the room. This story used to comfort him. He’d think, As long as I got through class without a bag over my head, things are under control. But now, as his students file past him, he knows that if they had a large enough bag, they wouldn’t hesitate to use it.