Just when you think start to think that Fountain might be a closet optimist (yay, Faison and Billy got to kiss goodbye, they'll make it after all…), he ends the book on a totally ominous note:
Billy nods and turns to the window. He knows he will never see Faison again, but how can he know? How does anyone ever know anything—the past is a fog that breathes out ghost after ghost, the present a freeway thunder run at 90 mph, which makes the future the ultimate black hole of futile speculation. And yet he knows, at least he thinks he knows, he feels it seeded in the purest certainty of his grief as he finds his seat belt and snaps it shut, that snick like the final lock of a vast and complex system. He's in. Bound for the war. Good-bye, good-bye, good night, I love you all. He sits back, closes his eyes, and tries to think about nothing as the limo takes them away. (Proud.178)
Yeeeah. That's not a happy ending, folks.
Actually, it's not really an ending at all: Fountain doesn't tell us what will happen to Billy. We don't know whether he will come back from Iraq or not. We don't know what kind of life he will make for himself if he does make it back. The only thing Billy does know is that he's locked right into that big military-industrial machine driving pretty much all of American reality in the novel.
But that's kind of the point. At the beginning of the novel, Billy had a lot of questions about reality and the meaning of his life. He also had a lot of questions about whether the people back home in the States were living in actual reality or just some kind of weird virtual reality. Well, at the end of the novel, he still hasn't figured out the answer the first question (who has?), but his experience at the Thanksgiving Day Cowboys game has pretty much answered the second question.
So, assuming Billy does make it home alive, how will he live his life now that he's seen a reality most Americans have not? That's not just Billy's question—it's our question, or at least it's the question Ben Fountain wants us to ask ourselves. We've seen Billy's reality now, too. What will we do with that knowledge?