Question

Which line from Extremely Loud and Incredibly Close reveals a despondent tone?
I couldn’t reach it, obviously, so I moved over the chair with the tuxedo still on it, and then I went to my room to get the Collected Shakespeare set that Grandma bought for me when she found out that I was going to be Yorick....
I stood on all of that and it worked for a second. But then I had the tips of my fingers on the vase, and the tragedies started to wobble, and the tuxedo was incredibly distracting, and the next thing was that everything was on the floor . . .
I zipped myself all the way into the sleeping bag of myself, not because I was hurt, and not because I had broken something, but because they were cracking up.
I started to clean everything up, and that was when I noticed something else weird. In the middle of all of that glass was a little envelope, about the size of a wireless Internet card.

Answer 1

The third line: "I zipped myself all the way into the sleeping bag of myself, not because I was hurt, and not because I had broken something, but because they were cracking up."

Why: the image of retreating into a "sleeping bag of myself" shows withdrawal and emotional self-protection; hiding because others are "cracking up" conveys humiliation and dejection, producing a despondent tone.