I found it hard to breathe. It was such a natural thing—breathing—I’d done it without even trying since the second I was born. But I seemed to have forgotten how. I pressed my hand on my chest, pushing as if my lungs had a reset button. But the only thing that came out was a high-pitched noise.

“Bex?” Charlie’s face swam into my vision. “Look at me, Bex.”

“Marcus,” I said between heavy breaths. “Zombie.”

“Yes,” Charlie said sadly. “He is.”

I scurried over to the small window in the door. Ms. Happel loomed on the other side, her jaw hanging low, her cat sweater twinkling. Beyond her was that exit door we’d needed so badly. And beside her was Marcus. His hazel eyes, which I’d always found so dreamy, were now a deadly gray.

I squeezed my eyes shut. Nope. This wasn’t happening. But when I reopened them, Marcus was still a zombie. Tip: Denial does not work.

Tears streamed down my cheeks. So I had my first kinda, sorta, maybe, could-be boyfriend, and he turned into a zombie. Story of my life. I clenched my fists as the shock wore off and morphed into anger.

“How is this happening?” I yelled. “Another disaster in our town. Another time everyone around me is in danger.”

“You are really not a lucky person,” Willa said.

“Thanks for pointing that out,” I snapped. “It’s appreciated.”

“You know those people who win the lottery multiple times?” she said. “You’re like them, except in a bad way.”

I started to pace, pulling my hands through my hair.

“How can you joke around at a time like this?” Charlie asked Willa. “Marcus is a zombie. And it’s not Bex’s fault—she didn’t even play the game—but our friend is gone forever.”

She shrugged. “I don’t think he is.”

I stopped pacing and stared at her.

“Hear me out,” she said. “This was caused by the Zombie Town game, right?”

Charlie shrugged. “We’re assuming.”

“And what was the object of the game? I’m sure you heard people talking about it.”

I wiped tears off my cheek with the sleeve of my sweater. “To cure the zombies.”

“Right. So maybe . . .”

“We can cure him with the game.” I stopped sniffling as hope rose in my chest.

But Charlie was still frowning. “I don’t know,” he said. “The Alien Invasion game didn’t work on real, live aliens. What if Zombie Town doesn’t work on real zombies?”

Willa glanced down at the floor, silent.

It was a risk to go out there and try to cure Marcus. Whoever went could get bitten and end up a zombie, too. And if the game didn’t work, that meant you were a zombie forever.

But I felt like this was my fault. I told everyone not to get weapons. It was my idea to go through the classrooms. It was my scream that had caused everyone to laugh and attract the zombie into the room. And even though I couldn’t think of any reason why, I felt responsible for the game affecting the real world. After all, it was my monsters that had escaped from Monsters Unleashed. It was my phone that had summoned aliens to town from Alien Invasion. This was my fault, too. Somehow. Probably.

I lifted my chin. “I’ll do it. I’ll play the game and try to cure Marcus.”

Charlie dashed over to my side. “That’s not a good idea, Bex. Let’s just wait it out. We’ll keep trying phone numbers until someone answers. Maybe someone will come get us.”

“I don’t want to wait,” I said.

“But what if the game turns you into a zombie, too?” Charlie asked. “All the other players turned.”

“We don’t know if that would happen, though,” I said. “Maybe you have to play for a really long time.”

Willa spoke up. “I don’t think so.”

“Why not?” Charlie asked.

“Think about it. People have been playing this game for weeks, right? Some people played it a little bit here and there, some people played it for hours on end, but everyone got sick and then turned into a zombie on the same day. If the game continuously turned people into zombies after playing it for a certain amount of time, people would have changed on different days. Not all at once. It’s like . . . a switch flipped.”

My hands curled into fists. “Veratrum did something.”

Willa nodded. “That’s my theory.”

“So if that’s right, then the switch—or code, or whatever—already happened and I won’t turn into a zombie if I play the game now,” I said.

“But we can’t know that for sure!” Charlie insisted.

I took a deep breath. “It’s worth the risk to save Marcus. This is my responsibility. I’ll do it.”

I slid my phone out of my pocket, went to the App Store, found the game, and hit Download. Willa chewed on her fingernail. Charlie drummed his fingers on the teacher’s desk.

“Okay, it’s installed,” I said.

Charlie peered over my shoulder, “I watched my brother play. Its functionality is just like Monsters Unleashed. You toss the cure at a zombie. A direct hit to the face works best. If you hit an arm or shoulder, it may bounce off. Oh, and the zombies can deflect. So you need to be quick and accurate.”

“And the cure is all for fictional, video game zombies,” Willa reminded me. “We have no idea how the game will work on real zombies.”

“If it even will,” Charlie added. “Are you sure about this?”

My eyes went to the window again. Marcus was shuffling back and forth in front of the exit, his head at an unnatural angle. I had to try.

“Yeah, I’m sure.”

I opened the game. The Zombie Town logo took over the screen. It included a cowering girl and a gory-looking zombie looming over her. Creepy horror music came out of the phone’s speaker.

“That’s reassuring,” I said.

Willa put her hands on my shoulders and forced me to look her in the eye. “It’s a game. Like all the other games you’ve played. You’re the best gamer I know. You’ve got this.”

I was glad she was confident because my legs suddenly felt as stable as cooked spaghetti.

“Close the door behind me as fast as possible,” I said. “If anything happens to me, just stay in here.”

Willa nodded, her mouth tight. I could tell she was trying not to look scared so I wouldn’t feel scared. Charlie wouldn’t even look at me. His eyes focused on a desk in the corner, and they were glistening like they were just about to fill with tears.

“I’ll be fine,” I said. “I’m sure Willa is right. The point of the game is to cure the zombies. This will work.”

I snuck up to the door as quietly as possible and peeked through the window. Ms. Happel had moved on down the hall, her shuffling frame only a shadow in the distance. But Marcus was still here. He seemed to be lumbering around in a mindless circle, even bumping into the wall now and then. My heart cinched. Marcus had such a brilliant mind. Was it still in there somewhere? Would he come back to us?

With one last deep breath, I glanced down at the phone. It was ready, locked, and loaded. I turned the handle of the door and crept out into the hall.

Charlie and Willa closed the door behind me. I could feel their eyes on my back, watching me with their hearts in their throat. But I felt strangely, suddenly calm.

Marcus hadn’t heard or seen me yet. I aimed the phone until his back was in the center of the target. Then I used my finger to swipe up and launch a cure.

On the screen, the “cures” were little science beakers. I wasn’t expecting that actual lab equipment would pop out of my phone and hit Marcus in the head. I didn’t know what I was expecting. But something happened: A ray of light came from my phone, where the flashlight beam comes from. But it was bright red, like a laser, and it hit Marcus’s right shoulder.

And he moved.

He’d been actually hit by something. Some force of light. And he was really, really, unhappy about it. He twisted around, baring his teeth, and growling. His hungry eyes lit up when they saw me.

And not in the way you want your crush’s eyes to light up when he sees you.

I launched another cure. This one hit him in the leg. He stumbled a bit but kept advancing—and certainly wasn’t cured. I aimed again and tossed one that seemed to be heading in the right direction but—being a zombie—he staggered a step and it glanced off his arm.

The game was doing something in the real world—making a zombie mad! Even more mad than, you know, usual zombie rage. Marcus was so close now. I could run, but Ms. Happel was down that hall somewhere. I had to stand my ground and keep trying.

It would have been easier if this wasn’t my first time playing the game. Stupid pact!

I took a deep breath, aimed the phone, and focused. Right in the head. Square in that handsome face. My finger swiped. The red ray of light streamed out of my phone . . . and got him right in the forehead.

He stood completely still, stunned. Then, as I watched, his eyes turned from that strange gray back to hazel. He blinked slowly, coming out of his zombie state.

“It worked, guys,” I whispered, waving my hand. “It’s safe to come out.” I wanted to yell and cheer, but we needed to be quiet. We didn’t want to catch the attention of Ms. Happel or Mr. Durr again.

Charlie and Willa poked their heads out of the door, then tiptoed out.

“It really worked?” Charlie asked hesitantly. “He’s not a zombie?”

Just then, Marcus raised his hands, curled them into claws, and groaned, “Brainssssss . . .”

Willa gasped. Charlie put his fists up like he was going to box three rounds with the zombie. But Marcus, rather than lunging for our brains, bent over at the waist, laughing uncontrollably.

“You guys are so gullible,” he said.

Willa punched him in the arm. “That wasn’t funny!”

“Yeah,” I said. “We were really worried that the cure didn’t work and that you’d be stuck like that forever.”

“Wait,” he said, confusion falling over his face. “Stuck like what?” He glanced around, like he just realized where he was. “What am I doing here?”

“What’s the last thing you remember?” Charlie asked.

Marcus yawned as he thought for a moment. “I walked to school this morning. No one was here because everyone was sick with that flu. And now I’m here with you guys.”

“You don’t remember zombie Robbie?” Willa asked in disbelief. “And zombie Mr. Durr? And zombie Ms. Happel biting your shoulder?”

He reached a hand up and squeezed. “My shoulder does hurt.” He started to sway in place. “Wow, you guys. I’m really tired.”

And then he collapsed to the floor.