Recognize This One?

Idling around at Amazon, I stumbled on a matching quiz: identify first lines from items in the Library of America. Here's one of my all-time favorites--if not the best opener ever, certainly a contender:

Some fine day I'll have to pay, Dennis thought, you can't sacrifice everything in life to curiosity. For that was the demon behind his every deed, the reason for his kindness to beggars, organ-grinders, old ladies, and little children, his urgent need to know what they were knowing, see, hear, feel what they were sensing, for a brief moment to be them. It was the motivating vice of his career, the whole horrid reason for his writing, and some day he warned himself he must pay for this barter in souls.

Recognize it? Check here (link).