3

“Goofballs,” I said, “we’ve got ourselves an awesome new mystery.”

We ran right away to our teacher, Mrs. Lang, and told her our plan. She agreed, then added, “I used to teach kindergarten, you know.”

“Do you have any advice?” asked Mara.

“Get a good night’s sleep tonight,” Mrs. Lang said with a sigh. “You’ll need it.”

When we left the classroom, Kelly said, “There’s only one real way to pretend to be as smart as undercover teachers —”

Brian held up his hand. “Don’t say it. I knew you’d ask me to teach you everything I know. Sorry, I can’t.”

“Why not?” I asked. “Because what you know is so scary?”

“Because what you know would make us nuts?” asked Kelly.

“Because our brains would throw up?” asked Mara.

“No, no, and maybe,” said Brian, “it’s because my brain is so huge, the government has classified it. It’s a secret. Even from me.”

“That explains so much,” I said.

“Exactly,” said Brian. “My brain is so big, it’s hard for me not to explain so much.”

Kelly grumbled. “The real best place to learn is the school library. Follow me.”

“M-E,” Brian said. “I am so good at this.”

We marched upstairs to the second floor. There were workmen crawling everywhere, pounding, sawing, painting, trying to finish the new classrooms in only one more day.

I wrote that down in my cluebook because you never know if something means something until it means it. Which sounded good, so I wrote that down, too.

When we got to the library, the door was shut tight.

“The library is never closed,” said Kelly.

We knocked.

We knocked again.

We knocked again again.

The door opened a crack. Mr. Silver, the librarian, popped out his head. “Hello?”

“Our free period’s half over and we need to learn stuff,” said Brian.

“Slide in,” he said. After we slid in one by one, he closed the door tightly behind us.

“I’m keeping the door closed because of all the dust from the construction,” he said. “Look.” Then he shook his head, and a shower of white dust fell onto his shoes.

“Now, how can I help you?” he asked.

“We need to know everything teachers know,” said Mara. “We have … a half hour.”

Mr. Silver blinked. “I see. Well, the best way to do that is for each of you to pick a favorite subject. What do you like to do?”

“Art,” said Mara. “Because I draw very well, and art is where fashion comes from, and I do fashion very well, too.”

“I’d be so great at art,” said Brian. “But I don’t want to be right now.”

“I’ll take history,” said Kelly.

“I know so much history!” Brian groaned. “Right now I’m thinking of bananas, and the last banana I had was this morning. That’s historical.”

“You’re bananas,” Kelly said. “I’m doing history.”

I looked at the shelves stretching to the back of the room. “Reading and writing for me.”

“I was going to do those!” said Brian. “But I could never figure out which came first, reading or writing.”

“Really?” said Mr. Silver.

“Think about it,” Brian said. “Reading couldn’t come before writing because there would be nothing to read. But writing couldn’t come before reading because writers couldn’t read what they wrote.”

We all stared at him.

“It’s a riddle,” Brian said.

“So are you,” said Kelly.

“Why not take math and science?” asked Mr. Silver.

Brian beamed. “Yes! I’m already an almost world-class celebrity inventor of inventions.”

So for the next thirty minutes, we read books and wrote notes and made pictures and looked up stuff and looked down stuff and looked at stuff from every angle.

The library wasn’t as quiet as it normally is. The workmen kept up their noises the entire time.

“All that drilling and pounding and banging is making my brain want to explode,” Mr. Silver said.

“My brain wants to explode right now,” Brian said, “but the government won’t let it.”

We were so deep in studying that we almost didn’t hear the bell ring, but by the end of the afternoon, the four of us equaled one pretty good teacher.

“Goofball mystery solvers,” I said, “tomorrow morning at nine sharp, we report for duty in room Four-K.”

“Our first day as undercover teachers,” said Mara. “I can’t wait.”

“Our students will be so smart by the end of the day,” said Kelly, “Principal Higgins won’t even believe it.”

Brian grumbled. “I already don’t believe it. I’m starting to forget everything I just read!”