"You had green spots?" Waldo echoed, and Ben gulped.
If Miss Bungle hadn't turned purple, then her sickness was different.
That meant Waldo's talk potion could have caused the epidemic after all.
Mr. Freaky hurried into the lobby with the health inspector.
The principal beamed when he saw Miss Bungle. "I thought you were still ill!"
"I'm feeling better now," said Miss Bungle.
"I just stopped by to check on a few things. What is this purple epidemic?"
Mr. Freaky shook his head. "We don't know. I assumed you had it too."
She shook her head. "No."
"Miss Bungle!" the office ogre commanded. "You must leave at once!"
The health inspector narrowed his eyes.
"This is the teacher who's been out sick?"
"Yes." Mr. Freaky introduced her.
"You're not purple," the inspector said to Miss Bungle in a suspicious tone.
While the man scribbled on his clipboard, Ben turned toward Waldo.
"Come on!" he whispered.
They found a quiet spot in the hallway.
"Now we know my talk potion caused the epidemic," Waldo moaned.
"We have to find out who tried to ruin my experiment!
And we need a cure for this disease before it spreads to People Place."
Waldo glanced at the health inspector.
"The people are obviously worried about it.
Oh!" Waldo's glasses flew off his face. "I just thought of something!"
Ben was startled. "What?"
Waldo picked up his glasses and put them back on.
"There were two humans at the dance, remember?
And neither turned purple. So maybe . . ."
Just then the health inspector's phone rang.
"Hello? Oh no! That's terrible news.
Yes, sir. I'll get out of here right away. I'll meet you at the hospital."
The health inspector put the phone back in his pocket and rushed for the doorway.
"I can't stay here any longer," he called over his shoulder.
"Two people have turned purple!"
Ben sighed. "Now Mrs. Hubbletree and Dave, Jen's date, are purple too.
Sorry, Waldo, but your talk potion definitely caused this epidemic."
Waldo slumped. "You're right, Ben."
Mr. Icky's voice came over the loudspeaker.
"Time for dinner! Everyone, please report to the cafeteria.
We have frog brain stew, fried caterpillars, and pond scum soup."
Ben and Waldo walked down the crowded hallway.
"This is fun!" said a ghoul. "I love lockdowns!"
"Me too!" said a troll. "I can't wait to eat!"
Ben and Waldo arrived in the cafeteria and waited in line for their food.
"It smells good in here," said Ben.
Waldo sniffed. "Yeah, it does." He looked around.
A lot of monsters were already eating.
"You know what, Ben? It feels good in here too."
"What do you mean?" asked Ben.
"Look around," said Waldo. "Do you notice anything?"
Ben gazed at the tables.
"Watch this!" called a werewolf.
He held one of his nostrils shut and shot a fried caterpillar out of the other one.
His friends laughed hysterically.
Ben looked back at Waldo. "I don't notice anything unusual."
"Exactly!" said Waldo. "Everyone is acting as they normally do.
I don't think this is an epidemic at all.
We're not sick. We're just . . . purple."
Ben nodded. "I do feel fine." He thought for a moment.
"Okay, so we don't have to worry about a cure.
We just need to figure out who ruined your experiment."
"The school was pretty empty when we went to the lab," Waldo thought aloud.
"The witches on the dance committee were in the restroom upstairs getting ready.
The only monster we saw in the hallway was Jen."
Waldo gasped. "It could have been her, or . . . Maybe it was her date, Dave!"
"Maybe," said Ben. "He did get lost in the building."
Ben remembered how Mr. Creepy had suddenly appeared.
"What about the science teacher?"
Waldo shook his head. "No way Mr. Creepy would be involved."
He looked around the cafeteria. "It's too bad Monster Academy is in lockdown.
I wish we could sneak out to People Place and question Dave."
Ben smiled. "Actually, I might be able to go and question him.
Watch this." Concentrating, Ben moved his hand toward the wall.
Just as his hand reached the wall, light sparkled, and Ben's hand passed right through the wall!
Waldo's eyes went wide. "Wow!"
"I finally figured out how to do it," said Ben proudly.
"I'll sneak out, go to the hospital in People Place, and see what I can find out."
"What about the flu?" said Waldo. "You could spread it."
Ben shrugged. "I think it's a risk I have to take."
He floated toward the school's lobby.
First he tried opening the doors, but the office ogre had locked them tightly.
Ben glanced around. And then, sure that nobody was watching, he turned back to the doors and floated right through them.