The wizards appeared at 8:41 a.m. out of a cloudless blue sky. Dapper in their green plaid public school uniforms, they whooshed through the air on broomsticks, wands extended to defend against an incipient threat.

In unison, they intoned a solemn chant. Their words burned bright sigils into the air which swirled and coalesced into a glittering white sphere of light.

The light pulsed and flashed and shimmered. The crowd gathered on the ground below looked up. Some had noticed the wizards when they’d appeared and then dismissed them as some kind of publicity stunt; others had not yet spotted the riders in the sky. The brilliance of the light drew them all, burning away both skepticism and preoccupation.

Tourists dropped their digital cameras and began to shout. Commuters halted mid-rush, briefcases falling open to the ground, loosed papers stirring in the light air. Inside the Twin Towers, people rushed to the windows and stared out—the executives and the janitors, the security guards and the receptionists.

The onlookers could not see what was happening miles away, inside three planes still in flight. Box cutters had already been drawn. Pilots’ throats had been cut. Flight attendants had bled in the aisles. Remaining passengers wept and prayed.

The onlookers did not see the flashes of light that dazzled the passengers through their tears as more young wizards appeared between the seats in first class, wands at the ready. They did not see the shock on the terrorists’ faces as they were brought down by skinny, adolescent girls in knee socks who fixed them with sober gazes and chanted nonsense in stentorian tones.

One passenger, his hand trembling as it clutched his cell phone, stuttered over a bad connection. “My—oh my God, honey, these kids have—there are these boys and girls and—this light—!”

Girls in plaid took over the cockpits, frowned in confusion at the controls, and then resorted to flying the planes with their wands. One plane came down softly in D.C., floating to the ground on a soft, cotton cloud. The others, barreling along their murderous course through New York City, flew into the wizards’ mass of light. First one was engulfed, and then the other, their explosive energy dissipating harmlessly into the sky.

The New York-bound passengers found themselves on the ground, their luggage stacked in neat piles beside them. They blinked at the tourists and the commuters, and looked up at the tower windows where they could see the shapes of executives, janitors, security guards, and receptionists.

In the buildings, some workers began to stagger, afflicted by sudden, strange dizziness. They reached for the walls, the floors, their companions, anything stable to reassure them that they weren’t falling. Some stopped, dropped, and rolled, trying to extinguish non-existent flames. Others gasped for air though there was no smoke, or ran outside to escape debris that wasn’t falling. Dozens of firemen arrived on the scene on foot, out of breath, perplexed.

Young boys in short pants, their green blazers open over untucked white shirts, appeared nearby to control the panic. “It’s over now,” they said, with more brusqueness than empathy. “No need to bang on about it.”

A woman in a top floor office crawled out from under her desk. She dragged her gaze away from the vast, oppressive sky that crowded her window. Her adolescent savior regarded her with a bored, snaggle-toothed expression.

“You’re right,” she said, slowly. “It’s over. I don’t know what I was thinking.”

She pulled herself up and straightened her skirt. The nightmarish sequence in her head was fading. She could only remember flashes: her heel breaking in the stairwell, trampling feet, the pain of forcing her bruised and concussed body to stand, the realization that there was no escape, nowhere to go, nothing to do but limp back to the office and give herself to the whistling blue.

She kicked her pumps away as hard as she could. They flew across the office in parabolas, point over spike.

The snaggle-toothed boy gave her a look of distaste. “Mundanes are daft,” he muttered.

Floors below, a gawky young girl swept her cornrows back over the shoulder of her blazer, and rapped her fingers impatiently against her wand. She stood beside a man in a rumpled blue middle management suit, both of them watching a cleaning woman in a yellow dress who was pounding on a wall and screaming in Spanish.

The girl with the cornrows watched with revulsion. “Stop it,” she said. “Stop it!” She looked to the man in the blue suit. “Get her to calm down. She’s off her trolley.”

The man in the blue suit approached the woman gingerly. She was older, her black hair gone almost entirely white, eyes nested in wrinkles. He wanted to take her hand, partially to comfort her, but mostly because he needed comfort himself. He had a shadow memory of running with a broken arm, of spending months with nightmares and flashbacks. He’d grown up calling women like this one mama and tía and abuela, and she was the only person nearby who looked like family.

“Está bien,” he said. “No sé que pasó, pero ya ha terminado.”

The woman stopped banging on the wall. She glanced suspiciously at the girl with the cornrows, and said quietly to the man, “¿Quiénes son?”

He couldn’t keep himself from glancing back, too. That was stupid; he didn’t want her to catch him looking suspicious. Something in his gut told him it would be a bad idea to upset these children. Luckily, she wasn’t watching them, just staring out of the window with bored aggravation.

“¿Qué quieren?”

“Quizás nada,” he answered, but his gut did not believe it.

The girl with the cornrows looked over. “What are you talking about?”

The man in the blue suit ran his dry tongue across his teeth. “She wants to know what you want.”

The girl shrugged. “You don’t get owt for nowt.”

She took a step toward them and the woman in yellow flinched backward against the wall. The girl rolled her eyes.

“At least you got her to shut her gob,” she said.

“La gente siempre quieren algo,” the woman in yellow said in a very low voice. The man in the blue suit nodded briefly, and gave in to the desire to reach for her hand.

Across the country, other shadow memories surged with emotional ferocity, and then faded. A man in a turban no longer felt the pain of being shot outside of his gas station in Mesa, Arizona. A father of four breathed more easily in Detroit; a father of eight hugged his children in California; a Bangladeshi immigrant wept as he touched his unblinded eyes.

The survivors drifted out of the buildings and gathered on the pavement outside. Dozens of wizards were already there. The youngest wandered through the crowds of people, observing them with the curiosity of zoo patrons as they summoned treats for themselves, cotton candy and caramel corn and funnel cakes. Adolescents were trooping out from their work in the tower, drifting into cliques as they gossiped about the barmy things, mundanes.

The older teenagers formed a loose circle in the shadow of the twin summits, their broomsticks held like scepters. Their bodies were trim and athletic beneath tidily buttoned blazers. Each pair of slacks and each knee-length skirt had been ironed with vigor, creases regimentally sharp.

They began to tap their broomsticks percussively on the ground, summoning the attention of the crowd. People left off talking and snapping pictures and making confused cell phone calls to loved ones. Some still shook and wept from the physical effects of events that had no longer happened; others shushed them and pushed them to the back of the crowd.

The oldest boy, straight-backed and willow-tall with tousled blond hair and flawless white teeth, held out his arms for the other wizards to cease their drumbeat.

“Everything’s going to be all right,” he declaimed to the crowd. His accent echoed with sterling silver and stone corridors and the acreage of forested estates. His prefect’s badge glinted harshly in the light. “Nothing like this will ever happen again.”

The crowd murmured. Among the exclamations of delight, there were a few dissonant mutterings. “Have you always been able to do this?” asked a woman, pitching her voice to carry. “Why haven’t you ever helped before?” She wore an A-line flowered sundress, and her boarding pass from San Francisco still stuck out of her pocket. “The Holocaust . . . Pearl Harbor . . . The quake!”

Her voice was shaking with emotion, but the blond boy only flashed a gracious smile. “We’re terribly sorry. We had things to do, you see. Evil wizards and magical border disputes and all that rot.”

“More important than the Holocaust?” asked the woman in the flowered dress.

“So many people . . .” said someone else. He looked the same age as the prefect, perhaps just finishing high school or starting college, skinny in over-sized jeans and a hoodie. In comparison to the teenage wizards, he looked weedy and under-grown. His eyes were glazed with loss of some description, and his voice was fragile. “You’ve had this power all along? You could have stopped them all?”

The blond boy’s face darkened. “Now see here, my man. We had things to do.” This time his voice had a hard edge to it, a clear warning that further questioning would not be welcome. “You’re being dashed ungrateful.”

Protests began to gather, many people speaking at once. The youngest wizards, who had begun entertaining themselves with strings and cards once they finished their funnel cakes, edged away from the crowd. They popped quietly out of sight and reappeared inside the surrounding buildings, noses pressed to the glass so they could still watch.

The inner circle of wizards tightened. They braced their brooms against each other, end to end. Those of the human crowd who were close enough could hear them murmuring to each other about how this had been a bloody stupid idea. The triumvirate of wizards on Mons Montis were wankers. Overthrowing thousands of years of separation for “noblesse oblige” . . . if the mundanes were going to go aggro over nothing then they deserved to die in their stupid wars.

Four of the wizards, each facing a different cardinal direction, tucked their brooms under their arms and drew their wands. They drew quick figures in the air. The sound of magic sizzled.

The crowd’s objections foundered as the spell took hold. The blond boy stared at them from beneath furrowed brows, his gaze icy and disappointed. The crowd stirred with guilt. Their concerns about the revelations of the magic world began to feel petty. Hadn’t the boy been reasonable? Generous, even? It was ungrateful to continue shouting. What ingrates they were, demanding to be saved from everything. Couldn’t they accept that the wizards knew better than they did? Hadn’t they seen their power?

The wizards relaxed, shifting their grips on their brooms. The blond boy’s smile returned, bright as titanium white from a tube.

“We’re here now,” he repeated. “There’s no need for you to worry anymore. Everything’s right as rain.”

He gestured to a group of three girls, their hair in pigtails of black and red and brown. Each performed a pirouette while waving her wand, and all at once there was a carnival in the street, with candy floss and ginger beer, and doe-eyed witches standing in kiss-me booths.

There was a moment of silence, but only one, before the last of the tension dissolved. Laughing, the crowd dispersed to eat and drink.

The woman whose office was on a top tower floor rubbed her bare feet, which were hot and scratchy from standing on the cement. She felt short without her heels. A black cat with balloons tied to its tail wended its way past, and she bent to pet it.

As she straightened, she caught a glimpse of the snaggle-toothed boy who’d found her in her office, now wandering past, sipping lemonade. He didn’t even look her way, but while she watched him, she couldn’t help but picture his face from earlier that day. The boredom and distaste in his expression, his tone when he said, Mundanes are daft.

The boy passed out of sight, the magic took hold in her mind again, and the ungrateful thoughts disappeared from her head. She bent down to pet another black cat. It purred.

Out by the carnival games, the man in the rumpled blue suit promised to win a stuffed Pegasus for a little girl from Indiana with no front teeth. There was a long line to play toss the ring around the frog, but in the meantime, there was flavored ice to lick and jugglers to watch. Nearby, a pair of receptionists were smoking together, angled so that the breeze would carry the smoke away from the line.

“Can you believe some people?” one receptionist asked the other. “They save our lives, and people want to argue about it?”

The second shook her head. “Exactly. Is this the time to talk about the Holocaust? They’re here now.”

The first agreed, “Better late than never.”

They exhaled synchronously. Twin streams of smoke blew away from them.

A wizard passed by with a tray of ginger beer, shouting “Free refreshments!” and both receptionists took one. So did the man in the rumpled blue suit. He looked around for the woman in the yellow dress, but he’d lost her in the crowd, and he couldn’t find her now.

The blond boy marched at the front of a ticker tape parade, accepting roses from blushing young women, and grinning at the captivated onlookers. So what if the mundanes were ungrateful—saving people still made you feel good. The triumvirate on Mons Montis said that times were changing, and since it would be harder and harder to stay hidden, it was imperative they take the initiative. The mundanes would just have to accept it.

At the end of the parade route, he and his friends embarked on their broomsticks and took to the air, winding agilely around each other like birds at play. The sky was blue, and the day was beautiful, and the crowd stared up at them with shining eyes.