Once the immediate shock and fear of the terrorist attacks of September 11, 2001, subsided into wary anxiety, it became clear that what that day demanded, above all, was interpretation. Only if we knew what September 11 meant — to its perpetrators, to its immediate victims, and to the nation that was its ultimate, intended victim — could we know how to respond, both individually and collectively. This instability of meaning is what made the attack on the Pentagon and the World Trade Center different from the earlier national tragedies to which it was compared — for instance, the attack on Pearl Harbor. December 7, 1941, was immediately legible: It was an act of war by one state against another, and there was no doubt about what would follow. September 11 was, and to a large degree remains, a coded and symbolic declaration, whose meaning and implications vary widely from one observer to the next.

The loudest interpreters of the attacks, as usual, were politicians and pundits. But there is something truly impressive about the way novelists have insisted on their own right to confront and explain history. For two generations, at least, we have been told that novelists are relics, mere craftsmen of narrative in an age of mass production. The novel was doomed to go the way of poetry, a semiprecious hobby unplugged from the live wires of the culture. Yet during the last five and a half years, almost all of our best novelists have written books explicitly or implicitly about September 11 — some good, some bad, but all unflinching in the face of the largest, most urgent questions. And as history teaches, it is the novelists’ interpretations of our moment that will testify on our behalf to posterity, long after the official explanations have gone brittle.

So far we have had post-September 11 novels from John Updike, Thomas Pynchon, Philip Roth, Salman Rushdie, Ian McEwan, and more. But the writer who seemed best equipped to respond to our paranoid moment, whose September 11 novel seemed most necessary, was Don DeLillo. Mr. DeLillo, more than any other novelist, has always worked at the intersection of public terror and private fear. His novels explore the way disaster, mediated through television, becomes experience: the Kennedy assassination in “Libra,” the “airborne toxic event” in “White Noise,” the atom bomb in “Underworld.”

Mr. DeLillo has even envisioned the writer and the terrorist as direct rivals, each seeking the power to change history by changing the way it is understood. As he told an interviewer in 1985, “There is a deep narrative structure to terrorist acts, and they infiltrate and alter consciousness in ways that writers used to aspire to.” This insight, which once might have seemed paradoxical or frivolous, now looks like a simple statement of fact. Terror, we have learned during the last five years, regards individual bodies as a medium through which to affect the collective imagination. That is why the terrorist can so savagely disregard his victims’ suffering, and why resistance to terrorism is always also an affirmation of humanism.

Now, in “Falling Man,” (Scribner, 246 pages, $26), Mr. DeLillo has finally given us his book about September 11. In fact, he has written about that day more directly and concretely than most other novelists have dared. Instead of approaching the attack on the World Trade Center through parable, like Mr. Roth, or analogy, like Mr. Rushdie, or phantasmagoria, like Mr. Pynchon, Mr. DeLillo confronts it head-on, with graphic realism. The novel begins with a prose transcription of the video images we all know so well: “It was not a street anymore but a world, and space of falling ash and near night. He was walking north through rubble and mud and there were people running past holding towels to their faces or jackets over their heads.”

If these opening sentences put the reader there on the “street,” ground-level with events, they also point to Mr. DeLillo’s concern with the “world” those events created. Surprisingly, however, the world that fascinates him is not the shadowy realm of political conspiracies, where so much of his earlier work has flourished. Mr. DeLillo is surprisingly, and happily, untempted by the idea of writing a secret history of September 11. Instead, his new novel is a surprisingly earnest and straightforward inquiry into the emotional effects of the attacks on the lives of victims and survivors.

“Falling Man,” then, offers neither the sprawling historical canvas of “Underworld,” nor the thesis-driven postmodernism of “Libra” and “Mao II.” Instead, like Mr. DeLillo’s last two novels — “Cosmopolis” and “The Body Artist,” neither very well received — the new book is small-scale and subdued, at times even a bit airless. Reading “Falling Man,” it is easy to see what Mr. DeLillo meant when he said that “the major influences on me have been European movies, and jazz, and Abstract Expressionism.” The book is structured like a film, a series of brief episodes that fade in and black out. Indeed, the main characters — Keith Neudecker, a lawyer who worked in the towers, and his ex-wife, Lianne — each have moments of estrangement when they view themselves as if they were actors in a movie. “In the movie version,” Keith thinks as he climbs the stairs to his deserted apartment in Lower Manhattan, “someone would be in the building, an emotionally damaged woman or a homeless old man, and there would be dialogue and close-ups.”

Dialogue and close-ups are, in fact, Mr. DeLillo’s preferred narrative tools. He keeps a tight focus on Keith and Lianne, in regular alternation, as they move through the days and weeks after September 11. And his prose eschews special effects, acting instead as a bleak, lustreless lens. Here is Keith picking a fight in a department store: “The man was listening to his companion but did not move. Keith was happy to stand and watch and then he wasn’t. He walked over there and punched the man.” This sounds more like Hemingway than what we usually think of as Mr. DeLillo’s style, and the long stretches of curt, repetitive dialogue sometimes read like a parody of David Mamet.

Yet this style serves Mr. DeLillo’s purpose, which is to write about a world reduced by horror to a kind of elective mutism. It is the prose equivalent of Keith’s state of mind: “He used to want to fly out of self-awareness, day and night, a body in raw motion. Now he finds himself drifting into spells of reflection, thinking not in clear units, hard and linked, but only absorbing what comes, drawing things out of time and memory and into some dim space that bears his collected experience.”

Mr. DeLillo’s aim in “Falling Man” is almost that of a lyric poet — not so much to tell a story as to evoke a state of mind. What we learn about Keith and Lianne, and their families, friends, and neighbors, is kept to a deliberate minimum. We know them less as people with histories than as psychic litmus strips, dipped into the poison of September 11 and brought out blanched with dread. When we first glimpse Keith, he is literally drained of color, covered in ash from the collapsing towers. He managed to escape after the first plane hit, but his friend and poker buddy Rumsey died in his arms, and he can’t stop reliving the Dantesque procession down the stairwell — thousands of office workers who know they might already be dead.

The shock of that morning leads him back to his ex-wife’s apartment, even though he had abandoned her years before. For Lianne, Keith’s reappearance is at first too strange and portentous to speculate about; then she starts to get used to it, and they drift back into what looks like normal married life. In fact, as Mr. DeLillo insistently shows, they are barely conscious of each other, almost a pair of zombies: “She was continuing to withdraw, but calmly, in control. He was self-sequestered, as always.”

Keith, an inveterate adulterer, starts a new kind of affair, with Florence, a woman whose briefcase he accidentally carried home on September 11. But sex with Florence means less to him than their sessions of storytelling, in which they endlessly relive the trek down the stairs. These passages are some of the best in the novel, showing that Mr. DeLillo has absorbed the survivors’ accounts and raised them to the universality of myth, or nightmare: “They were moving out of the worst of the smoke now and this is when she saw a dog, a blind man and a guide dog, not far ahead, and it was like something out of the Bible, she thought.”

By focusing so single-mindedly on this anesthetized aftermath, however, “Falling Man” ends up feeling willed and shrunken. Everything that happens in the novel, the reader comes to realize, will serve to echo back the general chorus of stunned grief. Keith and Lianne’s son Justin starts talking in monosyllables, a child’s whim that is also a metaphor: “It helps me go slow when I think,” he explains. Lianne leads a writing therapy group for Alzheimer’s patients, themselves victims of a terrified slowness. By the time Keith quits his job to become a professional poker player — a job that enforces silence and isolation, while immersing him in risk — the reader may well feel that Mr. DeLillo’s metaphors have turned tyrant.

Mr. DeLillo’s insistence that the only appropriate response to September 11 was brooding silence seems surprising, coming from a writer who in the past has been obsessively articulate. Events like the Kennedy assassination or the Soviet nuclear test seemed to Mr. DeLillo to demand proliferating narratives, conspiratorial in their restless sweep; history, he suggested, makes us compulsive explainers. Perhaps the most striking thing about “Falling Man” is the way September 11, a far more intimate and frightening eruption of history, drives Mr. DeLillo to the opposite extreme.

Indeed, the only parts of the novel that do not carry conviction, that seem to belong to another book, are the few chapters that attempt to inhabit the minds of the September 11 terrorists — showing them training in Hamburg or undercover in Florida. Here Mr. DeLillo’s psychology turns shallow and abstract: “Everything here was twisted, hypocrite, the West corrupt of mind and body,” thinks the terrorist Hammad. No more than Mr. Updike in “Terrorist” is Mr. DeLillo able to enter sympathetically into the mind of a killer.

His portrait of the victims is more intimate and truthful, but it too is sharply limited. For the weeks after September 11 were not, for most people, a time of moody silence. They were a time of great loquacity, of debating and planning and fantasizing. At times, Mr. DeLillo’s quietness even feels like a kind of showing off, an attitudinizing grief that is never wholly unaware of its own sleek profile. “Falling Man” does succeed in telling part of the truth about September 11 and its aftermath. But it would be a better novel if Mr. DeLillo weren’t so convinced that he’s telling the whole truth.

akirsch@nysun.com