The STEM Night Disaster

by Kate Biberdorf

  Birdie put her arm on my shoulder. “It’s okay, Kate. I can warm it up and reshape it. It’s a special modeling kind of beeswax. That strawberry will be fine.”

  “Thanks, Birdie. You’re the best, really. But . . . do you think someone is messing with my stuff on purpose?” Feeling unsteady, I walked up to my teacher and told her what happened.

  “I’m sorry, Kate,” she said. “But I didn’t see anyone go near your cubby. And I’ve been in the classroom all day. Except for during my lunch and part of my planning period.”

  “So, it could have happened then,” I said.

  “I don’t think so,” she said. “Someone would have to be awfully sneaky. Maybe when you stuffed it into the cubby you accidentally smushed it a bit.”

  “Maybe,” I said. But I didn’t think so. I had been so careful. Plus, this came after the missing lemons. I might have been able to shrug off one mystery, but two? This seemed deliberate.

  During science lab, I could barely concentrate on my project. All I could think about was catching the culprit.

  “I think we should set a trap,” I said to Elijah and Birdie. “Like a giant mousetrap that would spring on their hand.”

  “They would be caught red-handed, that’s for sure,” said Elijah.

  “You guys,” said Birdie. “I don’t think setting a trap is a very good idea. Don’t you think this person would see it? I mean, if it were big and all?”

  “I know,” I said. “Maybe we could convince Mrs. Eberlin to install a hidden camera in the classroom. And we could get video footage.”

  “Then we’d have to watch hours of your cubby,” said Birdie.

  “It might not be so bad,” said Elijah. “Sometimes on YouTube my mom watches this channel that’s just a video of a babbling stream. It’s called the Calm Channel.”

  “I don’t think watching Kate’s cubby would be calm.” Birdie let out an exasperated sigh.

  “It’s okay,” I said. “I’ll figure out some other way to catch the culprit.”

  CHAPTER ELEVEN

  A Strawberry on Top

  Heat (noun). From a chemistry standpoint, heat is energy flowing from a hotter system to a cooler one. If you give off energy, things heat up. If you take it away, things cool down. That’s why if you do a hundred jumping jacks, you’ll start to sweat.

  “I HAVE SOMETHING FOR YOU,” said Birdie on Friday at lunch.

  “What?” I asked. We sat in the cafeteria away from everyone, behind the wilty salad bar.

  Normally, we sat at a long table in a big group. But I wanted a little chance to relax. It still felt like someone was out to get me. And I had no idea who or why.

  Birdie held out a white paper bag.

  I pressed my hands together. “Please, Birdie. You know I have zero patience. Tell me what’s in there. I’m begging you!”

  “Close your eyes and count to ten.”

  “Okay, fine.” I squeezed my eyes shut. And started to count. “One Michigan,” I began. “Two Michigan.”

  I could hear Birdie opening the bag.

  “Three Michigan.”

  The sound of more paper crinkling.

  “Four Michigan. I can’t stand it. Five, six, seven, eight, nine-ten,” I rushed, then fluttered my eyes open.

  And there sitting on top of Birdie’s palm was my strawberry candle.

  It looked just like it had before. Only better, if that was possible. “That looks amazing. So real. I mean, I actually want to eat it.”

  “You think it’s your wax strawberry. It’s a real one,” she said with a serious voice.

  “Really?”

  “Just kidding. But it does look real, doesn’t it?”

  “Yes,” I admitted. “I could almost forget that it was ever messed up. Like maybe it was just a figment of my imagination.”

  “It wasn’t your imagination,” said Birdie firmly. “It looked like someone warmed it up in their hands and then squeezed it really hard to smash it.” Birdie bit into her taco. “I just don’t get who would do something like that.”

  “Me either. Maybe it was a hungry rat who was confused.”

  “Ha ha. That’s weird.”

  “What’s weird is the way Rory is looking over at me.” I nodded over to the table where he sat with Elijah and a bunch of guys. Rory peered at me again and then looked away when I tried to catch his eye. Then he whispered to Memito.

  “Okay. That is weird,” whispered Birdie.

  “I know.” At that moment, as if Rory knew we were talking about him, he snuck a glance at me one more time. I gave him a questioning look and he whipped around.

  “Weirder,” I said.

  “Agreed,” said Birdie, dipping her spoon in some rice pudding, which was dusted with cocoa powder.

  “Hold up! That’s cocoa powder.”

  “Yummy. And pretty.”

  “And also, a great tool.” I remembered a Dr. Caroline episode about dusting for fingerprints with cocoa powder. I explained how it worked to Birdie and then I zipped to the lunch counter. Mrs. Andrews, who manages the cafeteria, was sealing the lid on a jar of mayonnaise.

  “Can I please have some cocoa powder? Just a small cup. It’s for a really good reason. A science experiment.”

  “Science, huh?” She looked at me. She looked over at a plastic container of cocoa. “I don’t see why not. Is it for class, Kate, or are you doing something on your own? Your mom told me about your kitchen science experiments earlier this week.”

  I smiled at her. It’s always a little weird that the grown-ups at school know things about me that I didn’t tell them. But sometimes it’s kind of nice, too.

  “There’s a science project competition, one week from this Friday.” I pointed to a banner in the cafeteria that read: STEM NIGHT! NOV. 20!

  “Oh right!” She measured out a cup and handed it to me in a baggie. “Good luck!”

  “Thanks.” Back at the table, I turned to Birdie. “Sometimes having your mom as principal has some perks.” As fast as we could, we went to Mrs. Eberlin’s classroom, which was always open to students at lunch.

  We said hi to Mrs. Eberlin, who stood in the middle of the classroom with a stack of books in her arms.

  “What are you girls up to?” she asked as she strolled toward the back of the classroom.

  “Oh, just a little science,” I said, which was the truth.

  “Well, have fun, girls. I’m going to do a little reshelving.” She disappeared behind a bookshelf area we call the book nook. “Holler if you need anything.”

  “We will,” I said.

  Explaining the procedure to Birdie, I quickly gathered everything we needed (luckily Birdie always has art supplies in her backpack and it was cold enough out that we had gloves in our jacket pockets):

  2 pairs of gloves—to avoid putting our prints all over everything, or getting cocoa powder all over us

  1 tablespoon of cocoa powder—not to make hot chocolate but to dust for fingerprints

  1 paintbrush with soft bristles—to apply the cocoa powder, not for a Birdie masterpiece

  1 roll of tape—not to tape stuff together but to lift off the fingerprints

  1 index card—to stick the lifted fingerprint to for evidence

  Birdie pulled on a pair of purple gloves that she’d bedazzled with rhinestones. “My prints will not be contaminating the evidence.”

  “Definitely not.” I grabbed some of the cocoa powder and poured it into my cubby. Then I picked up the paintbrush.

  “How does it actually work?” asked Birdie.

  “Fingers are coated with sweat and oil. That means the powder will stick to it. Dark powder works best on a light surface.” After lightly swishing the brush back and forth, I gently blew away the excess powder. “Look!” I pointed to three fingerprints.

 
“Wow,” whispered Birdie.

  “I know.”

  Birdie cut off three strips of tape. “It’s time for liftoff.” Smoothing the strips over the prints, she pulled them off the surface of the cubby. Then she stuck the pieces of tape to the index card.

  Voila! We definitely had three perfect-looking prints.

  But I realized there were two problems:

  I had no idea if the prints were mine or someone else’s.

  If they were someone else’s, I didn’t have access to a fingerprint database.

  Luckily, I could take care of the first problem at home. The second one had me stumped.

  CHAPTER TWELVE

  Focusing on the Positive

  Positive charge (noun). When an atom is missing an electron or two, it will have a positive charge. It’s like having a balance scale with a pound of lollipops on one side and a pound of chocolate on the other. If you take away a lollipop, you’ll now have more chocolate than lollipops.

  AFTER SCHOOL, Elijah passed the soccer ball to me and I drove it down the field. The wind blew against my face. It was chilly outside, but I didn’t mind.

  Running with the ball felt good, almost easy.

  If only my science project felt that way, too. If only I could figure out who was messing with me.

  “You got this!” cheered Elijah.

  “Go, Kate!” shouted Avery, waving at me from the opposite side of the field. Streams of sunlight broke through the clouds.

  I got this, I told myself.

  But I wasn’t so sure. Rory stood in my way. I mean, he literally stood. He wasn’t coming at me. But more like standing still waving his arms, trying to intimidate me. On my team, I’m a defender, so I’m not as confident when it comes to duking it out. But I was going to have to speed past him. He was my obstacle. Calm down, I told myself. This isn’t a real game.

  It was just a pickup game after school.

  Tapping the ball to the side, I used a quick change of direction to scoot past him. Yes! I dribbled down the field. The goal was getting closer. Just as Jeremy tried to take possession, I kicked. The ball lifted off, arcing into the air and into the goal.

  “Oh yeah,” I cried, racing to grab the ball before I booted it back to midfield for the kickoff.

  Elijah high-fived me. Avery yelled “Goal!” and I saw the sunlight reflect off her sparkly red lip gloss, the latest color from her STEM project.

  “Hold up,” said Jeremy. “Are you actually saying that was a goal?”

  “Uh-huh!” I said. “It went right between the goal post markers.”

  “Dude, it did,” said Elijah. “I placed the rocks exactly where we always put the cones.”

  Jeremy folded his arms in front of his chest. He peered at Rory. “You were closer than me. Did you see it go between those rocks?”

  Rory stared at me. He looked at Jeremy and then he considered the goal. “Um, yeah. Sort of. I did.”

  “Sorry. I couldn’t see it,” said Jeremy. “This is why this school needs soccer nets!”

  “They would be helpful,” said Rory.

  Jeremy waved his arms emphatically. “We should have them. It’s basic equipment. If you win the STEM competition, you should also use the money to buy goals,” Jeremy said to Rory.

  Rory peered back toward the school. “Actually, I want to buy more books for the library. I’ve read every science fiction series in there.”

  “Me too,” I agreed. “I love sci-fi.”

  “Cool,” said Rory. “Uh, Kate, looks like your mom wants you.” Following his gaze, I spotted Mom, standing with Liam on the blacktop. She signaled it was time for us to go.

  “Okay, see you tomorrow, everyone,” I called out.

  “Don’t count this as a win because we didn’t finish,” Jeremy called after me.

  “Sure.” I jogged backward. “It doesn’t matter, anyway. We’ll beat you tomorrow, too.”

  “You wish!” shouted Jeremy.

  Elijah caught up to me. “Man, Jeremy is as competitive as you are.”

  “Yeah,” I admitted. “I definitely like to win.” Winning made me think of the STEM competition, which had been in my brain almost nonstop. I bit my lip and turned to Elijah. “I’m not sure I’m going to do so hot on the STEM competition, especially with someone sabotaging me. I just wish I knew who it was. Then I could stop them!”

  “Focus on the positive,” suggested Elijah.

  “Hmm. When I think of the positive, I think of a positive charge, which makes me think of my project, which makes me get worried all over again.” With a sigh, I folded my arms across my chest.

  “C’mon, Kate. Just think about what you’ll do with the money.”

  “I don’t know,” I mumbled.

  “How about buying more test tubes? Or lights and lasers for a musical talent show.”

  “Maybe. But I want it to be . . . you know, something that feels essential.”

  Everyone except me seemed to have great ways to spend the prize money. But it wouldn’t even matter if I didn’t figure out what was going on with my project. I’d never win if someone kept messing with my stuff.

  I tapped my pocket, which had the index card of fingerprints inside. Hopefully that would lead me to the answer.

  CHAPTER THIRTEEN

  Loops and Whorls

  Procedure (noun). The plan for how to conduct an experiment or demonstration. Think of it like a recipe for baking cupcakes. If you fail to follow a step (like adding the sugar), it won’t turn out very well.

  “LIAM, DO YOU WANT TO PLAY detective?” My brother and I munched on granola bars at the kitchen table after school.

  “Can I be a superhero and a detective?” he asked, popping the last bite of bar into his mouth.

  “Sure, why not—you can be a detective-superhero.”

  “Yes!” He zipped out of the kitchen. Five minutes later, he reappeared in his Batman pajama top with the cape attached.

  “You look ready!” I exclaimed.

  I showed him the fingerprint I had collected from my cubby. Then I explained how we were looking for a culprit based on a match. But that we had to identify my own print first to make sure the ones I collected weren’t mine.

  “So, the first thing I’m going to do is get my prints.” I pushed my thumb down into a pad of blue ink and then pressed it onto a white piece of paper. Then I did the same thing with the rest of my fingers. “Tada! Those are all my fingerprints. And it’s the first step in our procedure.” Then I wrote my name in big block letters under the print.

  “I want to do it too.” Liam rolled his thumb and his other fingers into the inkpad almost at once. “Tada!” he shouted. Grabbing a red crayon, he wrote his name in huge letters so that there wasn’t room for the M in Liam. Flipping his paper over, he wrote a giant M on the other side.

  I pointed to our prints. “See how they’re different? See the pattern of the loops and whorls?”

  He studied his thumbprint. “It looks like a little hill.” Then he examined mine. “Your center swirl is crooked. I want mine to be crooked too.”

  “Sorry, buddy. Can’t help you. That’s the thing about fingerprints. Every single person has a different one. Even twins.”

  “Hey, that’s like snowflakes. Ms. Chen taught us about that. Each one is unique.” Ms. Chen is Liam’s kindergarten teacher. She has a special handshake for each of her students. And Liam thinks she’s the coolest.

  “Your fingerprint patterns are formed before you were even born,” I explained.

  “When I was in Mommy’s tummy?”

  “Yup. Basically, we leave behind fingerprints all the time. On doorknobs, glasses, tables. But we can’t always see them with the naked eye.”

  He pointed to his eyes. “Unless you got x-ray vision. Like me—superhero detective boy.”


  “True,” I said. “Okay, now is the moment of truth. We’re going to see if there’s a match. Or whether someone else has had their hands in my cubby. It’s showtime!” If Elijah were here, he’d do a drumroll.

  My heart fluttered in anticipation.

  I compared the prints to mine. Also to Liam’s, because why not.

  Nothing matched up.

  They were completely different prints. All three of them were. Two looked like maybe pointer fingers and one was definitely a thumb.

  “It’s confirmed!” There was someone sabotaging me. Now there was just one problem. I didn’t know how to figure out who it could be.

  CHAPTER FOURTEEN

  A Volt and a Jolt

  Volt (noun). A unit used when measuring the amount of electricity in a battery. Something small like a remote control needs a few volts of electricity, but a remote-controlled car needs a LOT more.

  IT WAS THREE DAYS before STEM Night. On Tuesday afternoon, we were in the science lab, getting time for our projects with Ms. Daly. Like always, we had to work at a table with our assigned groups.

  “Okay, everyone, my Rube Goldberg machine is going to turn on that calculator.” I pointed to the calculator that Ms. Daly had given me.

  “I’m ready to watch this,” said Memito.

  “Me too,” said Jeremy.

  “Me three,” said Phoenix.

  The first thing I did was to power my very low-volt, handheld fan with a battery made from six lemons. This time I had remembered to roll the fresh lemons to soften up the insides before making my batteries. And to test them using the voltmeter.

  Now came the moment to see if my concept for the machine would work. I used blocks to prop up an upside-down lunch tray to the exact height of my little fan. Then I placed a small round pebble at the beginning of a Hot Wheels track on top of the tray. Then at the end of the track, I stacked six dominoes in a row. There was just enough space to carefully balance Birdie’s strawberry between the last domino and the very edge of the tray. Below the tray, I set a glass full of water.