We can't know whether Jessie is dead or not, whether her life has ended in some sort of Psycho-related horror: perhaps the man in the gallery killed her, inspired by the disjunction of cause and effect to murder the person he might instead have had dinner with. But we can't just leave her floating between possibilities, and her disappearance, and her father's sense of loss, are the same either way. DeLillo is not inviting us to think of inscrutable mysteries, he is asking us to weight the interpretative options, like a detective or an art historian. And weighing the options, of course, whichever side we come down on, we have already realised both of them to some degree. [. . .] We have only to hear the word "unthinkable" to start thinking--that's what the word is for--and all kinds of novelists and philosophers will remind us that Wittgenstein's excellent advice ("Whereof one cannot speak, thereof one must be silent") more often than not just can't be taken. ("The Paranoid Elite" London Review of Books [22 April, 2010], 40)This resonates, I think, with my comments on What Was Lost, in which Catherine O'Flynn short-circuits the readerly process of being forced to think the unthinkable, to imagine all the various interpretative options that result from a mysterious disappearance, when she gives in to the generic conventions of crime fiction by presenting us the case neatly solved, the cause and effect packaged together at the end of her book.
I've also been thinking of Joan Lindsay's Picnic at Hanging Rock, which I read many years ago but which struck me at the time because it defies the convention that suggests that the mystery (again of a missing girl, or here girls, in the desert) should be resolved by the end of the book. You reach the last page no wiser than when you began the first; although perhaps, precisely because you are left "hanging," in fact you are that little bit wiser than you would otherwise be.