When I was in high school, I remember how The Plague by Albert Camus had made so much impression on me. Well, I have forgotten most of the plot, if not all, but I very much liked the last paragraph of the book. I had the urge to search it on the web, and here is it:
And, indeed, as he listened to the cries of joy rising from the town, Rieux remembered that such joy is always imperiled. He knew what those jubilant crowds did not know but could have learned from books: that the plague bacillus never dies or disappears for good; that it can lie dormant for years and years in furniture and linen-chests; that it bides its time in bedrooms, cellars, trunks, and bookshelves; and that perhaps the day would come when, for the bane and the enlightening of men, it would rouse up its rats again and send them forth to die in a happy city.