“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.

“Come on,” Owen said, and she followed him out to the corner, where a guy wearing a dusty construction vest was helping a man in a pin-striped suit direct traffic, holding up the throngs of people to let a few cars slip through the intersection, then motioning for those on foot to continue their long treks homeward.

Lucy and Owen kept to the sidewalk, and when they reached the little bodega on Seventy-Fourth Street, which sold everything from cans of soda and dog food to toilet paper and lottery tickets, she grabbed his arm and dragged him inside. There were only a few bottles of water left, and they lined them up in a row on the counter before going back to grab a lighter and some candles, plus extra batteries for the flashlight.

When Lucy pushed some money toward the man behind the register, he gave her what seemed like an unlikely amount of change.

“I don’t think…” she began, but he flashed her a toothy smile.

“Blackout discount,” he said matter-of-factly.

“Who knew?” Owen said with a laugh. “Think that applies to any of the ice-cream shops, too?”

The man nodded as he packed their items into two plastic bags. “I heard the place on Seventy-Seventh is giving it away for free. It’s all melting anyhow.”

Owen turned to Lucy. “I think I like this city better in the dark.”

Outside, they stood for a moment with the plastic bags hooked around their fingers. The last streaks of pink had been erased from the sky over the Hudson, and an inky black had settled over the street. As they walked uptown to join the line for free ice cream, there was still a feeling of celebration to the evening. The price of beer at the bar next door was plummeting as the kegs grew warmer, and on the other side of Broadway, a restaurant was serving a makeshift dinner by candlelight. A few kids ran past with purple glow sticks, and two mounted policemen steered their wary-eyed horses through the crowds, surveying the scene from above.

As the line inched forward, Lucy glanced over at Owen, who was looking around with a dazed expression.

“You’d think there’d be looting or something,” he said. “In a place like this, you’d think it’d be mayhem. But it’s just a big party.”

“I told you it’s not so bad here,” Lucy said. “Give it a chance.”

“Okay,” he said with a little smile. “As long as you promise every night will be like this.”

“What,” she asked, “dark?”

“That’s the thing,” he said, looking up. “It’s not that dark. Not really.”

She followed his gaze to where the sliver of moon hung above the shadowy outline of the buildings, a thin curve of white against a navy sky that was dotted with stars. In all her years here, Lucy had never seen anything like it: a million points of light, all of them usually drowned out by the brilliant electricity of the city, the billboards and streetlights, the lasers and sirens, the fluorescent lamps and the neon bulbs, and the great white noise of it all, which left no room for anything else to break through.