“It’s not easy in the dark,” he said, but she didn’t respond. She’d been opening this door for nearly sixteen years. She knew the incremental movements by heart: the way the key stuck so that you had to jiggle it to the left and the noisy click of the bolt as it finally turned. She could have done this blindfolded. She could have done it in her sleep.

It wasn’t the dark. It was him.

As the lock finally gave and the door swung open, Lucy hesitated. She realized she’d never had a boy in her apartment before. At least not like this. Never alone. And certainly never in the dark.

There had always been friends of her brothers around, cleaning out the refrigerator and playing music so loud it thumped through the walls. But Lucy’s school was all-girls, so she’d never really had any guy friends of her own.

Of course, she’d never really had very many girl friends, either.

Last year, while making a rare and mandatory appearance as a chaperone at the winter formal, her mother had noticed that after a few obligatory dances, Lucy had disappeared into the hallway with a book. After that, she’d suddenly started paying attention to her daughter’s lack of a social life. If Lucy wasn’t hanging out with her brothers, she was usually just wandering the city by herself, neither of which were apparently productive uses of her time. And so she’d begrudgingly agreed to attend a basketball game, where a junior named Bernie, who went to their brother school, approached her at the snack booth to say that he liked her skirt. It was the exact same plaid skirt that every single other girl at the game was wearing, but he seemed nice enough, and she had nobody else to sit with, so she let him buy her a popcorn.

They started meeting behind the Metropolitan Museum of Art every day after school, doing their homework together just long enough to maintain the illusion that they weren’t only there to make out. But never once had he invited her over to his Fifth Avenue apartment, and never once had she considered inviting him back to hers. Theirs was a relationship built on neutral ground and impartial geography: park benches and stone fountains and picnic blankets. Bringing him into her home would have given the relationship a weight that it was never meant to bear, and it seemed to Lucy that there was no faster way to sink something. Especially something that would so easily sink on its own just two short months later, when Bernie met a different girl in a different plaid skirt at a different game.

But this was a unique situation, an emergency of sorts, and that changed everything. An ordinary afternoon had given way to an evening that felt hazy around the edges, tinged with recklessness and a kind of unfamiliar abandon. This was the first time she’d been left entirely on her own; no parents, no brothers, nobody at all. And now here she was, swinging the door wide open, a boy she barely knew waiting at her back.

From the front hallway, she could see all the way down past the kitchen and into the living room, where at this time of dusk, the windows were usually beginning to reflect the many lights of the city, a seemingly endless grid of yellow squares. But now it was empty, just a pale blue rectangle at the end of a long, black corridor.

Behind her, Owen cleared his throat. He was still standing just outside the door, apparently unsure whether or not he was being invited inside.

“So did you want to just grab the flashlight for me, or…?”

“No,” Lucy said, stepping aside. “Come on in.”

The fading light from the windows didn’t reach this far back into the apartment, so Lucy kept her hands outstretched as she moved tentatively into the kitchen. Owen had wandered into the living room, and she heard a scrape followed by a thud as he tripped over something.

“I’m okay,” he called out cheerfully.

“I’m so relieved,” she yelled back as she reached the pantry. On the bottom shelf, she found the enormous blue crate that held all the misfit items that never seemed to belong anywhere else. It was the one disorganized place in the whole apartment, a treasure trove of broken umbrellas and sunglasses and an assortment of pens from various hotels around the world. She rummaged through the debris until she found a single flashlight, and when she clicked it on, she was glad to discover that it worked.

Stepping out of the pantry, she swung the beam around the kitchen so that the light made shapes that lingered across the backs of her eyelids. In the living room, she found Owen standing at the window, his hands braced on the sill. When he twisted to face her, the cone of light fell directly across his face, and she lowered it again as he blinked.

“It’s so strange out there,” he said, jabbing his thumb behind him. “It seems so quiet without all the lights.”

Lucy moved to the window beside him, her nose inches from the glass. The sky was a deepening blue, and the checkerboard of windows, which were usually filled with glowing scenes of family dinners and flickering TVs, looked hunched and forsaken tonight. From where Lucy and Owen were standing, they could see dozens of buildings stretched across Seventy-Second Street, all of them made up of hundreds of windows, and behind them, thousands of people hidden deep within the folds of their own separate homes. It always made Lucy feel small, standing here on the edge of something so vast, but tonight was the first time it felt a little bit lonely, too, and she was suddenly grateful for Owen’s company.

“There was only one flashlight,” she said, and he glanced down at it. She waited for him to make some kind of joke about being afraid of the dark, and when he didn’t, when he simply remained silent instead, she added, “So maybe we should just stick together.”

He turned back to the window and nodded. “Okay,” he agreed. “But it’s already getting warm in here. Want to go for a walk before it’s too dark?”

“Outside?”

“Well, this is a pretty big apartment, but…”

“I just meant… I mean, do you think it’s safe?”

“This is your city,” he said with a smile. “You tell me.”

“I guess it’s probably fine,” she said. “And it wouldn’t hurt to pick up some supplies.”

“Supplies?”

“Yeah, like water and stuff. I don’t know. Isn’t that what you’re supposed to do in these types of situations?”

He dug around in his pocket and pulled out a few crumpled bills. “You can get as much water as you’d like,” he said. “I think a night like this calls for some ice cream.”

She rolled her eyes. “It’ll just melt,” she said, but he was undeterred.

“All the more reason to rescue it from such a sad fate…”

Before they left, they checked their cell phones, but neither had any reception, and Owen’s was nearly out of battery. Lucy used what little power was left on her laptop, which had been sitting unplugged on her bed all day, to try to send an e-mail to her parents, telling them everything was fine. But there was no connection, not that it probably mattered anyway; it was six hours later there, and if they weren’t still at some stuffy party, they were likely asleep.

Downstairs, Lucy and Owen burst out of the blazing heat of the stairwell into the lobby, which was nearly as humid. They almost ran over a beleaguered-looking nanny, who was paused with one hand on a stroller, steeling herself for the climb. A few other people were milling around near the mailroom, but it seemed as if most of the residents were either upstairs in their apartments or else still trying to find their way back home.

The handyman who’d helped rescue them was sitting at the front desk, his arm propped on his toolbox as he listened to a handheld radio, and he waved when he saw them. “How were the stairs?”

“Better than the elevator,” Owen said. “Any news?”

“No power until tomorrow at the earliest,” he reported, his mustache twitching. “They’re saying it goes all the way down to Delaware and all the way up into Canada.” He paused for a moment, then shook his head. “It must be quite a sight from up in space.”

“We’re going to pick up a few things,” Lucy said. “You need anything?”

The man was in the middle of requesting a six-pack of beer—which Lucy was about to tell him would be tricky to procure, given that they were both well under twenty-one—when Owen tapped her on the arm.

“Look,” he said, and she turned toward the front doors of the building, which faced out across Broadway. But instead of the usual herds of yellow taxis and black town cars and long city buses, she was shocked to see that the entire road was choked with people, the whole massive crowd moving uptown with a kind of plodding resolve.

Together, she and Owen stood in the doorway, their eyes wide as they watched the sea of bodies move past. Many of them were barefoot, their shoes tucked like footballs under their arms, and others had wrapped their shirts around their heads to try to keep cool. They wore suits and ties and dresses, and they carried briefcases and laptops, all of them taking part in the world’s strangest commute. There were no traffic lights to guide them, and no police in sight, though somewhere up the road, Lucy could see the faint throb of blue and red, unnaturally bright in the darkening sky.

“This is unbelievable,” she breathed, shaking her head. On the corner, one of the bars was jammed with people, many of them spilling out onto the sidewalks. Whether they’d given up on their way home or simply wandered outside to join in the camaraderie, there was a festive air to the gathering. High above them, perched on their balconies, people were using magazines for fans as they watched the scene unfolding below. Others hung out of their open windows, the apartments all dark behind them. It was like the whole city had been turned inside out.