He turned back to the stairs and searched for his mom. The screams and shouts for people to move, to get out of the way, made it impossible to hear. But her voice still rang in his ears. He remembered her last command, the plaintive look on her face, and hurried inside to find his father.

It was chaos beyond the doors, people running back and forth in the halls, loud voices arguing. Yani stood by the security gate, the large officer’s hair matted with sweat. Jimmy ran toward him. He clutched his elbow to pin his arm to his chest and keep his shoulder from swinging. The sting in his ribs made it difficult to take in a full breath. His heart was still pounding from the rush of the long fall.

“Yani—” Jimmy leaned against the security gate and gasped for air. It seemed to take a moment for the guard to register his existence. Yani’s eyes were wide; they darted back and forth. Jimmy noticed something in his hand, a pistol like the sheriff wore. “I need to get through,” Jimmy said. “I need to find Dad.”

The officer’s wild eyes settled on Jimmy. Yani was a good man, a friend of his father’s. His daughter was just two years younger than Jimmy. Their family came over for dinner around the holidays sometimes. But this was not that Yani. Some sort of terror seemed to have him by the throat.

“Yes,” he said, bobbing his head. “Your father. Won’t let me in. Won’t let any of us in. But you—” It seemed impossible, but Yani’s eyes grew wilder.

“Can you buzz me—?” Jimmy started to ask, nudging the turnstile.

Yani grabbed Jimmy by his collar. Jimmy was no small boy, was growing into his adult frame, but the massive guard practically lifted him over the turnstile like a sack of dirty laundry.

Jimmy struggled in the man’s fierce grip. Yani pressed the end of the pistol against Jimmy’s chest and dragged him down the hall. “I’ve got his boy!” he yelled. To whom, it wasn’t clear. Jimmy tried to twist free. He was hauled past offices in disarray. The entire level looked cleared out. He thought of the prevailing color on the stairway early on, all the coveralls in silver and gray, and feared for a moment that his father had been among those he’d passed. The crowd had been littered with people from this level, as though they’d been leading the charge—or were the ones being chased.

“I can’t breathe—” he tried to tell Yani. He got his feet beneath him, clutched the powerful man’s forearm, anything to take the pinch off his collar.

“Where’d you assholes go?” Yani screamed, glancing up and down the halls. “I need a hand with this—”

There was a clap like a thousand balloons popping at once, a deafening roar. Jimmy felt Yani lurch sideways as if kicked. The guard’s grip relaxed, allowing the blood to rush back to Jimmy’s head. Jimmy danced sideways as the large man tumbled over like a lush with too much gin in him. He crashed to the floor, gurgling and wheezing, the black pistol skittering across the tile.

“Jimmy!”

His father was at the end of the hall, half around a corner, a long black object under his armpit, a crutch that didn’t quite reach the floor. The end of this too-short crutch smoked as if it were on fire.

“Hurry, son!”

Jimmy cried out in relief. He stumbled away from Yani, who was writhing on the floor and making awful, inhuman sounds, and ran to his father, limping and clutching his arm.

“Where’s your mother?” his dad asked, peering down the hall.

“The stairs—” Jimmy fought for a breath. His pulse had blurred into a steady thrum. “Dad, what’s going on?”

“Inside. Inside.” He pulled Jimmy down the hall toward a large door of stainless steel. There were shouts from around the corner. His father was on full alert; Jimmy could see the veins standing out in his dad’s forehead, trickles of sweat beading beneath his thinning hair. His father keyed a code into the panel by the massive door. There was a whirring and a series of clunks before it opened a crack. His dad leaned into the door until there was room for the two of them to squeeze through. “C’mon, son. Move.”

Down the hall, someone yelled at them to stop. Boots clomped their way. Jimmy squeezed through the crack, was worried his dad might close him up in there, all alone, but his old man worked his way through as well, then leaned on the inside of the door.

“Push!” he said.

Jimmy pushed. He didn’t know why they were pushing, but he’d never seen his dad frightened before. It made his insides feel like jelly. The boots outside stomped closer. Someone yelled his father’s name. Someone yelled for Yani.

As the steel door slammed shut, a slap of hands hit the other side. There was a whir and a clunk once more. His dad keyed something into the pad, then hesitated. “A number,” he said, gasping for breath. “Four digits. Quick, son, a number you’ll remember.”

“One two one eight,” Jimmy said. Level twelve and level eighteen. Where he lived and where he went to school. His father keyed in the digits. There were muffled yells from the other side, soft ringing sounds from palms slapping futilely against the thick steel.

“Come with me,” his father said. “We’ve got to keep an eye on the cameras, find your mother.” He slung the black machine over his back, which Jimmy saw was a bigger version of the pistol. The end was no longer smoking. His father hadn’t kicked Yani from a distance; he had shot him.

Jimmy stood motionless while his father set off through the room of large black boxes. It dawned on him that he’d heard of the room. This was where his father had shadowed. The server room. The machines seemed to watch him as he stood there by the door. They were black sentries, quietly humming, standing guard.

Jimmy left the wall of stainless steel with its muffled slaps and muted shouts and hurried after his father. He had seen his dad’s office before, back down the hall and around a bend, but never this place. The room was huge. He favored one leg as he ran the full length of it, trying to pick his way through the servers and keep track of where his dad had gone. At the far wall, he rounded the last black box and found his dad kneeling on the floor as if in prayer. Bringing his hands up around his neck, his dad dug inside his coveralls and came out with a thin black cord. Something silver danced on the end of it.

“What about Mom?” Jimmy asked. He wondered how they would let her in with the rest of those guys outside. He wondered why his father was kneeling on the floor like that.

“Listen carefully,” his dad said. “This is the key to the silo. There are only two of these. Do not ever lose sight of it, okay?”

Jimmy watched as his father inserted the key into the back of one of the machines. “This is the comm hub,” his dad said. Jimmy had no idea what a comm hub was, only that they were going to hide inside of one. That was the plan. Get inside one of the black boxes until the noise went away. His dad turned the key as if unlocking something, did this three more times in three more slots, then pulled the panel away. Jimmy peered inside and watched his dad pull a lever. There was a grinding noise in the floor nearby.

“Keep this safe,” his father said. He squeezed Jimmy’s shoulder and handed him the lanyard with the key. Jimmy accepted it and studied the jagged piece of silver amid the coil of black cord. One side of the key formed a circle with three wedges inside, the symbol of the silo. He teased the lanyard into a hoop and pulled it down over his head, then watched his dad dig his fingers into the grating by their feet. A rectangle of flooring was lifted out to reveal darkness underneath.

“Go on. You first,” his father said. He waved at the hole in the ground and began unslinging the long pistol from his back. Jimmy shuffled forward a little and peered down. There were handholds on one wall. It was like a ladder, but much taller than any he’d ever seen.

“C’mon, son. We don’t have much time.”

Sitting on the edge of the grating, his feet hanging in the void, Jimmy reached for the steel rungs below and began the long descent.

The air beneath the floor was cool, the light dim. The horror and noise of the stairwell seemed to fade, and Jimmy was left with a sense of foreboding, of dread. Why was he being given this key? What was this place? He favored his injured arm and made slow but steady progress.

At the bottom of the ladder, he found a narrow passageway. There was a dim pulse of light at the far end. Looking up, he could see the outline of his father making his way down. The light above pulsed as well, a red throbbing, an unpleasant sight.

“Through there,” his father said, indicating the slender hallway. He left the long pistol leaned up against the ladder.

“Shouldn’t we cover the—?” Jimmy pointed up.

“I’ll get it on my way out. Let’s go, son.”

Jimmy turned and worked his way through the passage. There were wires and pipes running in parallel across the ceiling. A light ahead beat crimson. After twenty paces or so, the passage opened on a space that reminded him of the school stockroom. There were shelves along two walls. Two desks as well—one with a computer, the other with an open book. His dad went straight for the computer. “You were with your mother?” he asked.

Jimmy nodded. “She pulled me out of class. We got separated on the stairs.” He rubbed his sore shoulder while his father collapsed heavily into the chair in front of the desk. The computer screen was divided into four squares.

“Where did you lose her? How far up?”

“Two turns above thirty-four,” he said, remembering the fall.

Rather than reach for the mouse or keyboard, his father grabbed a black box studded with knobs and switches. There was a wire attached to the box that trailed off toward the back of the monitor. In one corner of the screen, Jimmy saw a moving picture of three men standing over someone lying still on the floor. It was real. It was an image, a window, like the cafeteria wallscreen. He was seeing a view of the hallway they’d just left.

“Fucking Yani,” his father muttered.

Jimmy’s eyes fell from the screen to stare at the back of his dad’s head. He’d heard his old man curse before, but never that word. His father’s shoulders were rising and falling as he took deep breaths. Jimmy returned his attention to the screen.

The four windows had become twelve. No, sixteen. His father leaned forward, his nose just inches from the monitor, and peered from one square to the next. His old hands worked the black box, which clicked as the knobs and dials were adjusted. Jimmy saw in every square the turmoil he’d witnessed on the stairway. From rail to post, the treads were packed with people. They surged upward. His father traced the squares with a finger, searching.

“Dad—”

“Shhh.”

“—what’s going on?”

“We’ve had a breach,” he said. “They’re trying to shut us down. You said it was two turns above the landing?”

“Yeah. But she was being carried up. It was hard to move. I went over the rail—”

The chair squeaked as his father turned and sized him up. His eyes fell to Jimmy’s arm, pinned against his chest. “You fell?”

“I’m okay. Dad, what’s going on? Trying to shut what down?”

His father returned his focus to the screen. A few clicks from the black box, and the squares flickered and changed. They now seemed to be peering through slightly different windows.

“They’re trying to shut down our silo,” his father said. “The bastards opened our airlock, said our gas supply was tainted— Wait. There she is.”

The many little windows became one. The view shifted slightly. Jimmy could see his mother pinned between a crush of people and the rail. Her mouth and chin were covered in blood. Gripping the rail and fighting for room, she lurched down one laborious step as the crowd coursed the other direction. It seemed as though everyone in the silo was trying to get topside. Jimmy’s father slapped the table and stood abruptly. “Wait here,” he said. He stepped toward the narrow passage, stopped, looked back at Jimmy, seemed to consider something. There was a strange shine in his eyes.

“Quick, now. Just in case.” He hurried the other direction, past Jimmy, and through a door leading out of the room. Jimmy hurried after him, frightened, confused, and limping.

“This is a lot like our stove,” his father said, patting an ancient thing in the corner of the next room. “Older model, but it works the same.” There was a wild look in his father’s eyes. He spun and indicated another door. “Storehouse, bunkroom, showers, all through there. Food enough to last four people for ten years. Be smart, son.”

“Dad— I don’t understand—”

“Tuck that key in,” his father said, pointing at Jimmy’s chest. Jimmy had left the lanyard outside of his coveralls. “Do not lose that key, okay? What’s the number you said you’d never forget?”

“Twelve-eighteen,” Jimmy said.

“Okay. Come in here. Let me show you how the radio works.”

Jimmy took a last look around this second room. He didn’t want to be left alone down there. That’s what his father was doing, leaving him down between the levels, hidden in the concrete. The world felt heavy all around him.

“I’ll come with you to get her,” he said, thinking of those men slapping their hands against the great steel door. His father couldn’t go alone, even with the big pistol.

“Don’t open the door for anyone but me or your mother,” his father said, ignoring his son’s pleas. “Now watch closely. We don’t have much time.” He indicated a box on the wall. The box was locked behind a metal cage, but there were some switches and dials on the outside. “Power’s here.” His father tapped one of the knobs. “Keep turning this way for volume.” His father did this, and the room was filled with an awful hiss. He pulled a device off the wall and handed it to Jimmy. It was attached to the noisy box by a wavy bit of stretchy cord. His dad grabbed another device from a rack on the wall. There were several of them there.