In the exact centre of this novel, poised, is a 10-page account of Philippe Petit’s preparation for his 1974 high-wire walk between the Twin Towers of the World Trade Centre. Colum McCann’s story of interlocking lives in New York is structured on either side of this interlude, and bears no direct relation to it, but it is the brief impossibility of Petit’s balancing act that holds it together. That breakfast time journey into space has, since 9/11, been widely mythologised, not least in Petit’s own account, To Reach the Clouds, and the recent documentary, Man on Wire, but it has waited 35 years for its full poetic drama to be inhabited in the sinew and cadence of McCann’s sentences:

“One foot on the wire - his better foot, the balancing foot. First he slid his toes, then his sole, then his heel. The cable nested between his big and second toes for grip. His slippers were thin, the soles made of buffalo hide. He paused there a moment, pulled the line tighter by the strength of his eyes. He played out the aluminium pole along his hands. The coolness rolled across his palm. The pole was 55 pounds, half the weight of a woman. She moved on his skin like water... he held the bar in muscular memory and in one flow went forward ...”

Out into the void, never once losing faith. Like Petit, the author had done some serious preparation of his own for this moment, this stepping out. From his first collection of stories, Fishing the Sloe-Black River, Colum McCann’s language has been all about precision and detail, the surprise of finding new ways never to put a foot wrong. He has been led before, by the nerve and grace of his style as much as anything, to gravity and its defiance; in Dancer, his fictional imagining of how it might have felt to be Rudolf Nureyev, McCann put his prose through all kinds of disciplined flight. He has readied himself.

In some senses, this new novel knocked at his door. McCann, who grew up in Dublin, and who has lived across Europe and in Mexico, settled in Manhattan more than a decade ago. On the morning of 11 September, his father-in-law had been working on the 59th floor of the north tower, the first to be hit. He got out, staggered uptown to his daughter’s place, ash-covered. McCann has recalled elsewhere how his own daughter, then four, went to hug her grandfather, and then recoiled at the smell of burning - she thought he was on fire.

That instinct - of the proximity of calamity - is as close as McCann’s book gets to the facts of 9/11. Until a coda set in 2006, the lives he describes are all played out in 1974, in the shadow of Petit’s crossing. But it is a “Twin Towers” novel none the less and, moreover, one to bear comparison with the very best - Joseph O’Neill’s Netherland, Clare Messud’s The Emperor’s Children.

Petit’s feat is mirrored in the book in the life of Corrigan, an Irish emigre to the Bronx who looks for his equilibrium in the riskiest of places. Corrigan is a pragmatic saver of souls; he tests his faith among the prostitutes and derelicts of a grim housing project in the Bronx. His story is told by his brother, Ciaran, who has followed him over from Dublin, a reluctant disciple. Corrigan does what he can - he lets the hookers use his bathroom, keeps the kettle on, spreads the possibility of lighter lives, is beaten to the point of martyrdom by the girls’ minders and pimps. Ciaran loves him but cannot fathom him; Corrigan is not quite of this world, though among the lowest and the lost, he dances somewhere above it all “like he was some bright hallelujah in the shitbox of what the world really was”.

In ways we never fully get to understand, Corrigan is eventually undone in his mission by seeing Petit on the wire, by the beauty or the contrast or just because. The watchers that day, in McCann’s imagining, were in two camps: those who secretly wanted to see the tightrope walker fall, a prefiguring of what those towers held in store - to “see someone arc downward all that distance, to disappear from the sight line, flail, smash to the ground and give the Wednesday an electricity, a meaning” - and those who “wanted the man to save himself, step backward into the arms of the cops instead of the sky”.

Petit, of course, defied both. Corrigan watches this display of human possibility and the next day he seems to brake at the wrong moment while driving on the freeway, the car behind clips him and in the second before their death Corrigan and his passenger, Jazzlyn, a young prostitute in a Day-Glo swimsuit, experience a proper kind of weightlessness for the only time in their lives.

McCann’s novel spools outward from this sudden and brutal rupture in unexpected ways; it lets us watch the lives destroyed by grief reassemble themselves, regain their balance. In describing Petit’s practice regime, mostly conducted in a meadow outside the city, McCann suggests that he only fell once in training, and that this in itself was necessary: “Once exactly, so he felt it couldn’t happen again, it was beyond possibility. In any work of beauty there had to be one small thread left hanging. But the fall had smashed several ribs, and sometimes when he took a deep breath, it was like a tiny reminder, a prod near his heart.” That heart pain, we come to see, subsequently prods away at all of those who see Corrigan fall “for real” in McCann’s fiction, and his death, in turn, becomes an allegory for the shock and aftermath of 9/11, for the city’s fall and its own new equilibrium.

None of this is forced, but it gives the novel (weirdly overlooked by the Booker committee) a proper weight and pull. McCann is at home in all of the lives he explores - the young artists who were driving the car that hit Corrigan’s van, undone by the picture of death; the mother of Jazzlyn, herself a prostitute, handcuffed at the funeral, imprisoned in her grief; and her orphaned grand-daughters, who grow through the tragedy and provide the book’s redemptive note. It has an epic and messy scope - at times it puts you in mind of DeLillo in full stride - but it is always startling in its particulars.

McCann describes the sensation that Petit feels on the highest wire as “another kind of awake”. There are many moments in his writing here when he too provides that kind of sharpness and, watching, you smile at the risk. McCann backs himself to step out into the spaces his novel opens up and it is always thrilling to follow him. Tacked inside Petit’s cabin door was a piece of wisdom that he lived by, one which this triumphant all-or-nothing novel also wears near to its heart: Nobody Falls Half-way.