Quentin spends most of the novel looking for Alaska… oops, we mean looking for Margo Roth Spiegelman. He finds her… but she says she doesn't want to be found. Well that's a letdown. When he asks her to come home with him, she says no. But he at least gets to make out with her in a parking lot before they part ways. After they kiss, Quentin gives us the last line of the novel:
Yes, I can see her almost perfectly in this cracked darkness. (3.22.178)
His staring at her reminds us of when they stared at each other in the darkness when they were kids. And the last line makes us recall another line from earlier in the book: Quentin says, "Margo's beauty was a kind of sealed vessel of perfection—uncracked and uncrackable" (1.5.37). But by the end of the novel, he sees that she isn't perfect. She isn't uncracked and uncrackable, she's in the "cracked darkness" (3.22.178). She might even be the cracked darkness.
But this doesn't scare Quentin away. He seems to accept her for who she really is, instead of trying to make her into something she's not. So while they may be parting ways, Quentin also might finally be her first true friend.