The official name of the housing complex, a wind-swept corridor of towers crammed with 17,000 people, is the Valley of Silver. Its nickname: the Slab.

“It’s very simple,” Mourad said. “There is a border between here and Paris, between rich and poor. And you can never really cross it.”

Mourad, 25, and his friends had taken refuge from the chill in a vestibule of an aging high-rise. Outside on the weather-beaten esplanade, mothers hunched behind strollers. Boys chased a soccer ball, breath steaming, near abandoned, rusty-shuttered storefronts. A pudgy Islamic fundamentalist — djellaba robe over tube socks and sneakers — carried groceries with his black-shrouded wife, whose veil revealed only her eyes.

The young men watched the esplanade, an expanse of walkways and plazas above street level, dingy tunnels for traffic below. It has been their playground, marketplace, battlefield. As Mourad sees it, the battle lines were drawn long before riots this fall made the Slab a stage in a national drama.

“They wait for the kids to get violent before looking for solutions,” said Mourad, a short, lean man with expressive brown eyes. “It’s not a question of justifying it. But how else do you want them to make themselves heard?”

The riots began Oct. 27 about 15 miles east of Argenteuil after the accidental electrocution of two teenagers hiding from police in a power substation. A rampage of arson and violence spread from the industrial belt of Paris across the country, lasting three weeks and causing about $240 million in damage, France’s worst unrest in decades.

This city of about 100,000 suffered less devastation than other areas: about 30 burned cars, some vandalism, scattered brawls. But the Slab played a powerful symbolic role in a clash between youths and the state.

Two days before the rioting started, France’s tough-talking interior minister came to town, accompanied by a phalanx of police and journalists. The minister, Nicolas Sarkozy, arrived at 10:30 p.m., an hour when the Slab can get rowdy.

He was met by about 200 youths shouting insults and throwing debris. During the uproar, Sarkozy referred to young hoodlums with a word that means “rabble” or “thugs.” The incident became a rallying cry for rioters nationwide.

“It was like he prepared a theatrical piece by coming late at night, during Ramadan, with all those riot police,” said Mourad, who was on the esplanade, but denies throwing anything. “It was a provocation. That was why the kids responded that way.”

Two nights later, in a quieter but emblematic incident, Mayor Georges Mothron left a meeting at the Slab to discover that arsonists had torched his car. As he stared at the charred vehicle, 15 young men surrounded him. After a few edgy moments — half-conversation, half-confrontation — a community activist came to the mayor’s aid.

Mourad, the mayor and the activist experienced a microcosm of France’s urban crisis in markedly different ways. Seen through their eyes, the Slab sheds stereotype and hyperbole and turns out to be less hostile and more hopeful than its image.

Mourad chided them quietly. He wore jeans and a black fatigue-style jacket zipped to his throat. He displayed a military ID card. A career in the army has steered him away from a gantlet of joblessness, drugs and prison. He has an apartment, a car, a girlfriend.

But modest success has only honed his resentment.

“I once gave this card to a policeman who stopped me to check my papers,” he said with a melancholy grin. “He laughed in my face. He thought it was some kind of joke. He took it to his supervisor, laughing. But when he came back, he was all pale. He saluted me. ‘Excuse me, I made a mistake.’ That kind of thing makes you angry.”