Falling Man, by Don DeLillo

The sprawling Dickensian story of 11 September 2001, with its grieving families, heroic firemen, "terror sex" (one-night stands in the aftermath), rampant patriotism, solemn mourning rituals and the growing sense of exasperation and boredom with the whole subject, has novelists queueing up. It is the kind of big subject Americans once claimed as their literary birthright - a journey down the Mississippi, the hunting of a whale, or a trek by landless farmers to California. Other than in Don DeLillo's Underworld a decade ago, American writers have backed off such grand national themes. Finely-chiselled novellas like Philip Roth's Everyman and DeLillo's The Body Artist have serious aims, but the scale is small, and the focus, as DeLillo suggests of a character in Falling Man, is "privileged, detached, self-involved white".

Among the dozen or so 9/11 novels so far, the destruction of the World Trade Center is an offstage event in a disintegrating marriage, with interior design by Infidelity & Rage (Jay McInerney's The Good Life and Ken Kalfus's A Disorder Peculiar to the Country), or a late and essentially mechanical resolution of the multiple ironies of urban life (Paul Auster's The Brooklyn Follies and Claire Messud's The Emperor's Children). They all address the near-universal belief that things will never be the same again with a worldly negative. Marriages go on, as do careers, infidelity, baby-sitting, and ambition.

It was ethnographers and sociologists who were the among the first to hold up a mirror to the city and its trauma, in rich novelistic detail. A Russell Sage Foundation research project into the impact of the attacks, led by historian Nancy Foner and others, was published in 2005 as Wounded City: The Social Impact of 9/11. Foner's researchers describe the largely autonomous worlds of bond traders, garment workers, taxi drivers, and firefighters living in the Rockaways. For many New Yorkers, the events strengthened community bonds. The researchers have other stories to tell, of fraying boundaries, political fragmentation, and the failure of social networks when confronted by a traumatic event.

Novelists today help us to understand a narrower, but more intense fragment of experience. In an essay published in December 2001, DeLillo briefly listed the detritus of the day, with "The paper that came streaming out of the towers and drifted across the river to Brooklyn backyards, status reports, résumés, insurance forms." For DeLillo, 9/11 has the capacity to serve as a monstrous metaphor for our civilisation.

Keith Neudecker, the central male character of his new novel Falling Man, emerges bloodied by fragments of glass out of the ash and rubble of the World Trade Center. He is one of the heroic survivors who is no hero, and who cannot find words to express what he has seen. He finds his way to the apartment of his estranged wife Lianne, and their son. It is an unforgettable opening scene. For a time Keith and Lianne try to mend their broken relationship, and he once again seeks to be a father to their son Justin.

But there are things now which he cannot share with his wife, or communicate with anyone except, briefly, with an African-American woman, also a survivor, named Florence Givens. He had picked up her briefcase by accident on the staircase of the North Tower and returns it to her. Their occasional conversations and lovemaking offer Keith the hope of another kind of reconciliation.

One afternoon, in the mattress department at Macy's, Keith overhears a slighting remark about Florence by another shopper. Keith punches the man, and they are soon brawling. Ready to play Florence's defender, Keith still walks out on their relationship with scarcely an explanation. Lianne wants to keep the family going. By being together they can live through things which scare and hurt them. He replies monosyllabically, "All right." Keith is a man who doesn't know how to be healed.

Before the attack, Keith had been a member of a weekly poker game. The arbitrary rules gave him perhaps the only meaningful structure in his life, and one which did not ask him how he was feeling. The novel ends with Keith, now a professional poker player, in a world in which human contacts are unwelcome. Living in hotel rooms, he works at the empty ritual of his wrist exercises. He has become, like Mr Tuttle in The Body Artist, "anonymous to himself".

Keith's story is interwoven with that of Lianne, a freelance book editor in Manhattan, and their son, traumatised by what has been done to their lives by "Bill Lawton" (the half-heard name of Bin Laden). Lianne is a volunteer tutor with a group of patients in the early stages of Alzheimer's, encouraging them to write of their memories. The progressive erosion of their memories disturbs Lianne. Her father, fearing his own loss of memory, committed suicide when she was a teenager. Lianne thought it had been for her, so she would never have to face the day he failed to know who she was.

Lianne's mother Nina, a retired art historian, has been in a long-term relationship with Martin, a European art dealer of uncertain provenance. After the attacks they argue about what enables men, in the name of God, to murder people in their thousands. Martin wants to talk about history, grievance, "lost lands, failed states... money, empire, oil, the narcissistic heart of the West". Lianne feels he understands the terrorists all too well. Perhaps he was really somebody else, a figure on the periphery of Baader-Meinhof or Red Brigade? "Maybe he was a terrorist but he was one of ours, she thought, and the thought chilled her, shamed her - one of ours, which meant godless, Western white." Sitting in a deserted church, Lianne, one of the godless, is comforted by the thought of belief, and alarmed at its consequences. "Once you believe such a thing, God is, then how can you escape, how survive the power of it...?"

Falling Man is an excavation deep into the heart of a world in which only fanatics and terrorists, with calm certainty, claim to grasp the sense of things. In the immediate aftermath of the plane crash above him in the World Trade Center, Keith saw a man in a striped shirt falling from the building. Richard Drew's troubling photo of that man, against the stark vertical side of the building, gives DeLillo a title, and a recurring trope: we are all there, with the falling man, in a world without safety nets or the hope of rescue. In this masterly novel, there is no redeeming clarity, only the attenuated dust of the collapsed towers.

Eric Homberger is professor of American Studies at UEA, Norwich