“Miss Balza,” I asked, “are you okay? You don’t look very happy.”

“I don’t feel very happy,” she said, “but now you and Connor are here, and that makes me feel better. I heard about how the two of you helped Mrs. Robinson find the lost library. And how you helped Mr. and Mrs. Lee find out who stole the diamond earrings from their store.” She bent down in front of us. “I’d like to hire the two of you.”

I squeezed Connor’s hands. This was so exciting—our third case. “Sure thing,” I said. “What’s the problem?”

“Someone has been playing pranks on the theater,” she said. “I need you to help me find the culprit.”

A culprit is someone who is responsible for doing something naughty. I liked that word a lot, but now wasn’t the time to say that to Miss Balza.

“We can help,” said Connor.

“Thank you so much!” She smiled a big, cheery smile.

One of the things I have learned about being a detective and solving a mystery is to get all the facts of the crime. “Miss Balza, could you please tell us what happened?”

“The first day of rehearsals, everything was fine. The trouble began on day two. Some of the props for the set were moved. And on day three, someone stapled the curtains shut. Yesterday the lightbulbs for the makeup table went missing. And today I found that someone had cut all the buttons off the costumes.” She sighed a heavy sigh. “It gets worse. Mr. Folopoulos said if we can’t stop the pranks, he’s going to shut down the play.”

“That’s terrible,” said Halmoni. “Everyone’s working so hard.”

“Can you think of anyone who would want to play these pranks?” asked Connor.

That was a good question, and it leads to the second thing I’ve learned about being a P.I. A person needs a motive. That’s a reason for doing what they did.

Miss Balza shook her head. “No. Everyone here is so nice and helpful.”

“Not everyone,” I said. “Someone here is playing pranks.”

“We should start with a list of everyone who is part of the play,” said Connor.

“We can check the master list in the office. It has everyone’s names and their jobs.” Miss Balza looked at Connor and said, “Oh my goodness! Connor, I’m so sorry! You need to be on stage in five minutes, not helping me.” Miss Balza looked at her clipboard. “Lark, you’re not onstage until this afternoon.”

“That’s good,” I said. “That means I have all morning to investigate.”

“I can investigate too,” Connor said. “I can watch from the stage and see if anyone is acting strange. Lark, when you’re done talking to Miss Balza, you can check around the theater for anything that seems suspicious.”

“That’s a great plan,” I told him. “Good luck with rehearsal!”

“Thanks,” he said and headed up to the stage.

Miss Balza and I went to her office to find her papers. We walked past my friends Franklin and Kate. They were with Loi. She babysits us when Mom, Dad and Halmoni go out. I really like her. She’s a teenager and in junior high, and she’s great at everything! Franklin, Kate and Loi were sitting in a circle, practicing their lines. I noticed they were making notes on their scripts with different-colored pens, like pink, purple, green, blue, red and black. What a great idea! When I saw Connor, I was going to tell him that was something we should do too.

I went into the office and said to Miss Balza, “Maybe someone is mad because they didn’t get a part. Do you have anything like that in your notes?”

“Hmm. Do you know Sophie?” she asked.

I nodded. Sophie is in my class. We are best friends—she just doesn’t know it yet.

“She tried out for the part of Alice, but Loi got it instead. Mrs. Wiedman auditioned for the role of the White Rabbit, but that went to Connor. Mr. Lee auditioned for the role of the Mad Hatter, but that went to Liam. Mrs. Wiedman, Mr. Lee and Sophie are the understudies,” said Miss Balza. “That means if Loi, Liam or Connor can’t perform, Sophie, Mr. Lee and Mrs. Wiedman would get to play those roles.”

“That’s a good motive for getting rid of Loi and Liam and Connor,” I said, “but not such a good motive for pranks.”

“That’s a good point.” She sighed.

“I should still double-check,” I said. I took out my detective notebook and wrote down their names. I have dyslexia. Which means letters and numbers can get mixed up in my head. Writing takes me a little longer, but I know if I’m patient I can do it.

Miss Balza’s phone beeped—and kept beeping. “Oh! That’s my alarm. Mr. Lee is bringing our morning snack, and he’s bringing hot dogs for lunch. I have to go or I’ll be late!”

She ran to find Mr. Lee and help with the food. Miss Balza had a job to do, and so did I. It was time to find the prankster.