I wanted to run up to meet it. I wanted to kill another incarnation of Ms. Vaughn. But I didn’t dare move until that school door was open. I couldn’t risk Maxfield locking the building down.

The car slowed to a stop. The driver stepped out. Ms. Vaughn again, this time wearing a business suit. She opened the back door and leaned inside.

The first person stepped out. A boy. Short, maybe thirteen or fourteen. He was wearing a bright red T-shirt and shorts. He was in handcuffs. That was different.

The second climbed out through the same door. Another boy, a little older. It looked like he was in pajamas. He had on handcuffs, too. They both looked terrified, but didn’t know what to do. They were captives, in the middle of nowhere, in a blizzard.

Ms. Vaughn stood in front of them, gesturing. I remembered her telling me how much I’d love it here, but these kids already knew it was a prison. She was probably threatening them, not reassuring them. A moment later she was in her car, the doors closed, and she began to drive. The boys watched her go, one of them already heading cautiously up the stairs and out of the falling snow.

I was ignoring the car now, my eyes glued on that door.

The other kid took a tentative step up.

The faces in the window were waving their arms in warning.

The door opened.

I jumped up, snow falling from my clothes as I sprinted out of the trees and across the snowy lawn. No one seemed to notice.

A girl appeared in the doorway. Red sweater, white shirt, gray skirt. For a moment I thought she actually was Becky.

One of the boys saw me, his handcuffed arms raised as he pointed me out to the other.

I glanced to the road. Ms. Vaughn’s car was out of sight.

I was almost to them now. The younger boy backed away, and the other called to me for help.

The girl stepped back, her hand gripping the door nervously.

“Don’t,” I bellowed, my voice dry and harsh.

There was fear in her eyes, but I was close now.

“Gabby!” I shouted. “Don’t close it. I’m here to help.”

The shovel wasn’t going to do me any good inside—there wouldn’t be enough room to swing it—so I dropped it on the stairs and pulled the Tasers from the pocket of my sweatshirt. I held one in each hand.

I took the steps two at a time. Gabby—the dupe—had no idea who I was, only that I knew her name. Her eyes were wide, but she was frozen in place. That was all I needed.

A moment later I was past her, inside the ornate front entry. I held out the Tasers like pistols, turning in a circle, watching for guards.

“Who are you?” she asked, her voice tiny. She was still standing on the top step, holding the door.

“This is all fake,” I said, checking the stairs and peeking down the corridor. “Half the people in this school aren’t real.”

Gabby didn’t answer.

No one was coming. I needed to get sent to detention, but I had no idea how the security contracts worked now, or whether there even were contracts. I stepped back to the door. I regretted what I was about to do, but I knew she wasn’t real—she was a robot. Gabby was back in the town.

I stuffed one of the Tasers into my pocket and pulled her back inside, grabbed her by the jaw, and shoved her against the wall. She began to shake, but that was exactly what I wanted. I needed her to be scared. I held the Taser up, inches from her face, and pulled the trigger, electricity popping and cracking. She closed her eyes, trying to turn away.

“No,” I shouted, shaking her. “Look at me. Look at me!”

One eye slowly opened. Her whole body was trembling, but she wasn’t fighting.

“I’m inside, Gabby,” I said. “Tell the others I’m inside. Tell Lily it’s time.”

She began to cry, and I let go of her.

There were voices on the stairs. I drew the second Taser again, and began backing up toward the basement.

“It’s all fake,” I shouted. “This school is run by robots.”

I must have sounded like a lunatic.

I kept waiting for Gabby to pop, for Maxfield to take her over and attack me, but she didn’t.

She couldn’t. All the new humans had just arrived. If they immediately saw one of their own revealed as a robot, the school would turn to chaos.

There were footsteps somewhere, the squeak of sneakers on marble.

I spun, trying to see which hall it came from.

“Gabby, Curtis, Carrie, Shelly, Harvard, Mouse—they’re not real,” I said. “They’re fake. They’re robots. Tapti, Eliana, Walnut …” I listed as many names as I could remember from the town. I didn’t know what good it would do. All I wanted was for someone to send me to detention or for Ms. Vaughn came back.

“We know,” someone said, and I looked up the stairs to see a boy I vaguely recognized. Not from school, but from the outside world.

A blond-haired girl appeared next to him, and then another. They looked almost identical. The sisters.

I recognized them instantly.

They were the daughters of the president of the United States. I stared—too long.

Lights exploded all around me, and I was on my face on the marble. Both Tasers flew from my hands, skittering across the smooth stone.

I rolled onto my back just in time for someone huge—Curtis!—to grab for my hands. I kicked him, driving my heel into his knee, and he fell.

“Get him!” Curtis yelled.

Finally.

I scrambled to my feet. Skiver and Walnut were thundering on the stairs, chasing me.

I needed to make it look like a mistake. I ran, pretending I didn’t know where I should go, and then darted down to the basement.

I didn’t want them to catch me until I was there—I didn’t want to give them a reason to search me. They just needed to throw me in detention and close the door.

The only weapon I had accessible was the fist spikes, and as I ran I fitted them into my hand. Three heavy nails, each protruding two inches past my fingers when I clenched my fist.

I could hear them running after me as we turned down the final corridor. The ceiling was low here, and the walls narrow. It was old concrete, and it smelled damp. I ran past door after door—empty, dark storage rooms—and finally turned to face them. I was maybe twenty feet from the detention elevator.

“You’re not real,” I said, smiling.

“Dude’s gone crazy,” Walnut said, the more nervous of the two.

Skiver kept coming, unarmed. I wondered whether he could tell my fist wasn’t just a fist.

“Skiver, I know you can see me,” I said, talking to the human. “This one’s for you.”

I lunged at the robot, my fist connecting with his gut. He shrieked as the spikes stabbed him, and he stared at me, his face contorted in pain. Walnut backed up, finally seeing I was armed.

“What?” Skiver stammered, holding his stomach.

And then he was gone. The pain disappeared from his face and he stepped toward me, completely unafraid. Skiver had popped.

I swung at him again, and he blocked my fist with his arm, the vicious spears gouging into his forearm. He ignored them and slammed me in the chest with the heel of his hand. I fell backward. It felt like he’d hit me with a hammer.

I gasped for breath. I’d lost the spikes now, too, and I scrambled away, trying to get back on my feet.

There was no time. The robot Skiver was on top of me, his fingers around my neck. He picked me up with one hand then threw me backward again. I didn’t have time to do anything. I couldn’t breathe. I couldn’t move.