The broom handle trick worked perfectly. Robbie seemed content to pace back and forth by the door, waiting to eat our brains—or at least, I assumed that’s what he wanted to do. So maybe we could safely find another way out.

“We could go out the back entrance,” Charlie suggested. “And then cut through the woods. That way we avoid the parking lot—and Robbie—entirely.”

“Sounds like a good plan,” I said, and Marcus nodded in agreement.

Willa chewed on her thumbnail. “But what if Robbie’s not the only one? What if there are more of . . . them inside here with us?”

Charlie scratched his head. “We’ll just have to be careful.”

We crept down the hall, elbow to elbow. The school didn’t look particularly sinister. It was daytime, for one thing, and all the lights were on. But walking by one empty classroom after another gave me the creeps.

A shuffling sound stopped us in our tracks. We neared the end of the hall, with only one room left—Ms. Happel’s English classroom. We all glanced around, searching one another’s faces for what to do. The sound continued and the lights went off in the classroom. A shadow cast its darkness across the doorway.

And Ms. Happel came out.

A totally human Ms. Happel.

She gasped, hand on her heart, as she saw us. Admittedly, we probably looked kind of creepy, standing completely still all in a row like that.

“Students! What are you doing?” She had her coat thrown over one arm, like she was on her way out, and she wore one of her many cat sweaters. Yes, many. This one had a cat’s face with sequins for eyes.

“We’re heading out the back way,” I said. “Another student is by the front door, acting strangely.”

She nodded somberly. “We have to move quickly. I’ve been watching out the window. There are several people acting . . . strangely. This flu seems to have a unique effect on them.”

That was one way to put it.

She closed her classroom door. “Let’s get out of here. Follow me.”

I had to admit, I felt a little better knowing an adult was now in charge. I’d tried calling my parents on their cell phones several times already but neither one had answered. I didn’t want to think about what that could mean. At least now Ms. Happel would take care of us.

We turned the corner, following our teacher closely, until she stopped short.

Farther down the hall stood Mr. Durr, my science teacher. He was standing still, sort of staring at a locker.

“Mr. Durr?” Ms. Happel called. “We’re heading out. Would you like to come with us?”

His head twisted toward the sound of her voice, and he started walking. It was the same shuffle-drag-shuffle that Robbie had done outside.

“Oh, no,” Charlie said.

The science teacher tilted his head to the side and a long string of drool leaked from his open mouth.

“He’s one of them!” Marcus yelled.

Before we could get away, Mr. Durr had reached Ms. Happel and grabbed her arm. She gasped and tried to pull it back, but he clamped down on it with his teeth.

The floor seemed to move underneath me. One of my teachers had just bit another. I couldn’t believe this was happening. My brain was screaming things like, Run, dummy! but my feet seemed glued to the floor.

Marcus, however, sprang into action. Letting out a roar, he slipped his backpack off his shoulder and swung it like a two-ton weapon at Mr. Durr’s head. To be fair, that thing was full of books and a laptop, so it was pretty heavy. And Mr. Durr went down—hard.

“Come on, Ms. Happel,” Willa said, pulling at her unbitten arm. “Let’s go!”

But the teacher stayed put, swaying in her spot.

“She must be in shock,” I said.

“Ms. Happel!” Charlie yelled. “We don’t know how long he’ll be down for. He’s going to get back up. We have to go!”

She blinked heavily, as if awakening from a deep slumber, and slowly turned her head to face us. Her dark eyes lightened until they were a pale, shimmering gray.

I stumbled backward, my hands reaching out to grab on to my friends.

“Is she—is she?” Marcus stammered.

As if in response, our sweet English teacher growled and snapped at the air.

“Run!” Charlie yelled.

We dashed into the nearest open classroom, slamming the door closed behind us. Ms. Happel pressed her forehead against the small glass window, but didn’t try the knob. Mr. Durr soon joined her. He had a small lump on his forehead from Marcus’s bag.

“We’re safe,” I said. “They can’t open doors.”

“Yeah, but we can’t stay in here forever,” Charlie said through ragged breaths.

“It’s the game,” Marcus said, pacing back and forth. “Zombie Town. It turned people into actual zombies.”

Willa slammed her hand on a desk, startling me. “So who did it?” she yelled. “Who broke our pact and played the game? Who set off this disaster?”

Marcus quickly shook his head.

“I didn’t,” Charlie and I said simultaneously, stumbling over each other’s words.

“Someone did this!” Willa screeched. “We made a promise to never play a Veratrum game again, but one of us did.”

I knew I hadn’t played. And I knew Charlie hadn’t played. Marcus seemed too busy lately creating that new game in the computer lab. And Willa had clearly kept her promise.

“I don’t think any of us played,” I said.

“That’s it,” Charlie said, slowly raising his eyes from the floor.

I turned to look at him. “What?”

“We haven’t really stopped to think about why we’re not zombies,” he said. “What do we have in common?”

It dawned on me instantly. “We didn’t play.”

Charlie nodded. “Everyone I know who got sick had played the game. Jason. Robbie. Even Mr. Durr talked about the game in class.”

“You’re right,” Willa said. “Chloe was addicted, and she was the first to puke in ballet class.”

“Both my parents played and they got sick last night,” Marcus said. “They were locked in their room this morning. I assumed they were sleeping. Does this mean that they’re zombies?”

I swallowed hard. That would mean my parents were zombies, too. “I think so,” I said sadly. Then I pushed the thought to the back of my mind.

“But it’s not just the people who played the game we should be worried about,” Charlie said. “The people who didn’t play aren’t safe either because they can become a zombie if they’re bitten. Mr. Durr just turned Ms. Happel!”

“No one is safe,” I croaked.

Marcus started pacing again. “We have to get out of here.”

“What can we use as weapons?” Willa asked.

Charlie tapped on his chin. “Do they have real knives in the cafeteria or only the plastic ones they give us?”

“They must have real knives for chopping and meal prep,” Marcus said.

“You guys!” I cried. “We are not going to stab anyone!”

“Then how are we going to get out of here?” Willa asked.

“We have to defend ourselves,” Charlie said.

Marcus moved closer to me. “Mr. Durr bit Ms. Happel and turned her into a zombie. You saw it.”

“There has to be another way.” I shook my head. “I know you’re focused on the whole zombie thing, but deep down, they’re still our teachers. And Robbie is still Robbie.” I took a deep breath. “If we came across my parents in the parking lot, would you hurt them, too?”

They all stared at one another and then at the floor. I didn’t want to know the answer.

“I’m calling 911,” Willa said.

We waited as she made the call. Scowling, she hung up and tried again. And again.

“What’s going on?” Charlie asked.

“Busy signal,” she said gravely. “Every time.”

Thoughts swirled in my head. We’d figured out that zombies couldn’t open doors. But then how did my parents get out of the house? I thought about the messily written message on the whiteboard and the answer came to me. One of them transformed first. The other wrote the warning to me and lured the zombie out of the house before turning, too. All to keep me safe. And it had worked.

My head snapped up. “I have an idea.”

Willa, Charlie, and Marcus circled around me.

“We know they can’t open doors, right? So we use that to our advantage.” I pointed at the side door. It didn’t lead to the hallway where our teachers stood waiting to devour us. It led to the classroom next door.

I continued, “Almost all the classrooms have connecting doors to the classroom beside it. We go from room to room, avoiding the hall. And when we’ve gone as far as we can, we run for it.”

My friends all looked at me, picturing it in their heads.

“It’s as good a plan as any,” Charlie said.

Marcus nodded. “Let’s do it.”

Willa grabbed a ruler from the teacher’s desk. Charlie raised his eyebrows at her, but she only clutched it more tightly.

“Hey, it’s better than no weapon at all.”