by David Lewman
“I don’t know,” Ava said. “Can I see it?”
“Sure,” Hannah said. She dug around in her backpack and came up with the plastic bag holding the feather. She opened the bag, took out the feather, and handed it to Ava.
Ava looked at the feather. Then she held it next to one of the feathers in her hair, comparing the colors. They were the same.
“It does look the same,” she admitted, handing it back to Hannah. “I guess it could have come from my hair.”
“Have you been by Mrs. Ramirez’s desk recently?” Ben asked.
Ava thought a minute. Then her face brightened. “Yeah,” she said. “I went up by her desk to turn in my magazine subscription money, just like everybody else. Maybe it fell off then.”
The three friends nodded. That made perfect sense.
Unfortunately, it didn’t get them any closer to catching the thief.
“Thanks, Ava,” Corey said. “You’ve been a big help.”
“I have?” she asked. “Great.” She stood there grinning at Corey, who smiled back awkwardly.
“Well,” he said, “we should probably get going. See you in homeroom.”
“See you.”
The members of Club CSI turned and started to walk away. But then Ava called to them.
“Oh, hey!” she said. “Can I have my feather back?”
Hannah looked at Ben and Corey. They nodded. The feather wasn’t really of any use to them now that they were pretty sure it didn’t come from the thief.
“Sure,” Hannah said, handing Ava the feather.
“Thanks,” Ava said. “And good luck with your investigation.”
“Thanks,” Ben said. “I think we’re going to need it.”
The three members of Club CSI sat in a school hallway that didn’t get much traffic. It led past some dusty cases full of old trophies to an exit that was kept locked.
They looked discouraged. Mainly because they were discouraged.
They had found a set of fingerprints they believed belonged to the thief. But they didn’t know whose fingerprints they were.
They had found a feather at the crime scene, but instead of an important clue, it had turned out to be a dead end. Like this hallway.
Corey tossed a ball up and caught it, over and over. Hannah twisted a strap on her backpack.
Ben decided they needed some cheering up. “Remember what Miss Hodges says,” he said.
“Leave investigating crime to the professionals?” Corey asked.
“I don’t think I remember her ever saying that,” Hannah said.
“Well, maybe she should have,” Corey countered.
“No,” Ben said. “She says to keep asking questions. As long as you’ve got another question to answer, your investigation is still alive.”
That was true. Hannah and Corey thought about what Ben had said. And then something occurred to Hannah.
“I’ve got a question,” she said.
“Okay,” Ben said. “Let’s hear it.”
“How did the thief steal the hundred dollars when the metal box it was in was locked?” she asked.
“Yeah,” Corey said, stopping his throwing for a minute. “And the desk drawer was locked too.”
“That’s a good question,” Ben said. “The locks didn’t look broken, so I’m guessing the thief picked them somehow.”
“So maybe we should be looking for someone who knows about locks,” Hannah suggested.
“Is it hard to pick locks?” Corey asked. “You hear people talking about picking locks, but I really have no idea how to do it.”
“Neither do I,” Hannah said. “Do you need some kind of special tools? Maybe the tools would lead us to the thief.”
Ben stood up. “I think we need to know more about locks and how to pick them. Maybe Miss Hodges will have an idea.”
Corey stood up too. “Well, if she knows as much about locks as she does about feathers, we should be all set.”
Hannah stood up, and they headed down the hall toward Miss Hodges’s office.
Miss Hodges was busy preparing her classes for the next week. But when the Club CSI members told her what they were interested in, she had an answer for them right away.
“You should go see my friend Chuck,” she said.
“Who’s he?” Corey asked.
“A locksmith,” Miss Hodges answered. She wrote something on a piece of paper and then handed it to Corey. “Here’s his address. It’s not far.”
Hannah half expected the locksmith shop to be a dark, greasy, dirty place. But when they opened the front door, they saw a clean, brightly lit store where everything seemed to be in place.
The older man behind the counter looked up from the lock he was working on, and smiled. “Afternoon!” he said. “May I help you?”
“We’d like to know how to pick locks!” Corey blurted out.
The smile disappeared from the man’s face. “Well, I’m afraid I’m not going to be able to help you with that, kids.”
Ben tried to explain. “We’re students in Miss Hodges’s forensic science class. She said you might be able to help us understand locks better, so we could figure out who stole some money at school.”
“Are you Chuck?” Hannah asked, trying her best to look nothing like a robber who planned to pick people’s locks.
“I sure am,” Chuck said, smiling again. “And Miss Hodges is a good friend of mine. If she said I should help you, then I guess it’s all right.”
“We appreciate it,” Ben said. “We realize we know pretty much nothing about locks.”
“Then we’ll start with the basics,” Chuck said. He reached down behind the counter and picked up a board with several labeled locks on it. He pointed to the different kinds of locks as he named them.
“Pin-and-tumbler lock, wafer tumbler lock, tubular lock, padlock . . .” The world of locks, like the world of feathers, seemed to be a big one. Chuck explained how some of the locks were much more difficult to pick than others.
“So,” he said. “This thief of yours. What kind of lock did he or she pick?”
“Well, first he or she picked the lock on a desk drawer,” Hannah said.
“Like a teacher’s desk? At school?” Chuck asked.
“Yes,” Corey said.
“Wooden or metal?” Chuck asked.
“Wood,” Corey said. “I mean, the desk was wood. The lock was metal. Of course.”
“Old or new?”
Corey thought a minute. “Old, I think. It looks kind of scratched and beat up.”
“Kind of like me!” Chuck said, laughing. “I’d have to see the lock to know exactly what kind it is. But I’m guessing it wouldn’t be too hard to pick.”
“Oh!” Hannah said suddenly. “I just remembered something! I have pictures of the lock on my phone.”
She dug out her phone from her backpack and then started searching through her recent photos until she found a decent close-up of the lock on Mrs. Ramirez’s desk drawer. She handed her phone to Chuck.
Lowering his reading glasses, he peered at the image on the small screen. “Okay, yeah,” he said. “That’s pretty much what I’d imagined. Not much of a lock, I’m afraid. It wouldn’t take an expert to pick that open with a small screwdriver and a paper clip.” He used his fingers to make the picture bigger. “In fact, I think I can make out scratch marks on the face of the lock. That’d be consistent with a screwdriver.”
In his mind Ben scolded himself for not examining the lock more closely. He should have looked at it with a magnifying glass. But to tell the truth, he’d been a little shy about using one in front of Corey’s homeroom classmates. He was afraid they’d think he was trying to be Sherlock Holmes. Even though he actually was.
“So, just to be clear, you’re saying it wouldn’t take any special tools or skills to pick open the lock on the desk drawer,” Hannah said.
“Exactly,” Chuck said, nodding.
“That’s too bad,” Corey said. “It doesn’t really help us tr
ack down the thief. Pretty much anyone could get their hands on a screwdriver and a paper clip.”
“That’s true,” Chuck said. “Anything else I can help you with?”
Hannah found another picture on her phone and showed it to Chuck. “There was another lock, a padlock.”
Chuck glanced at the picture. “Right. I know that brand. I carry it myself.” He leaned down, reaching into the display counter and pulling out a padlock just like the one on Mrs. Ramirez’s metal box.
“Now this lock,” he said, holding up the lock, “would be very hard to pick.”
“Then how did the thief get the box open?” Corey asked.
“Could he or she have known the combination?” Chuck asked.
“Good question,” Ben said.
As they walked away from Chuck’s locksmith shop, the three friends talked about what they’d learned.
“Who might know the combination to the padlock?” Hannah asked. “Did Mrs. Ramirez tell it to anyone?”
“Or did she maybe write it down and leave it somewhere, and the thief found it?” Ben asked.
Corey thought about this, then shook his head. “I don’t think so,” he said. “I doubt Mrs. Ramirez would tell anyone the combination. And since she has a great memory for numbers, she wouldn’t need to write it down. Besides, she used a formula to come up with the combination.”
Ben stopped walking along the sidewalk and turned toward Corey, excited. “What formula?”
“I don’t remember,” Corey said. “I just remember her telling us the formula. It was kind of like an equation or a math puzzle.”
“Did you figure it out?” Hannah asked.
“I didn’t even try,” Corey said. “I don’t like math puzzles. I can barely get all my math homework done as it is. I don’t want to do extra math just for fun.”
Ben started off down the sidewalk at a brisk pace.
“Where are you going?” Hannah called after him.
“Back to Mrs. Ramirez,” he yelled back over his shoulder. “It’s not quite five yet. Maybe she’s still in her classroom.”
Hannah and Corey hurried after him.
No,” Mrs. Ramirez said, shaking her head emphatically. “I definitely did not write down the combination. Anywhere.”
Corey nodded. “That’s what I told them.”
“We just have to cover all the bases,” Ben said apologetically. “It’s good to know the thief couldn’t have found the combination written down.”
Hannah, Corey, and Ben were in Mrs. Ramirez’s classroom. She had been grading quizzes when they found her. But she was happy to pause a little while to answer their questions. She wanted the missing money returned just as much as her students did. And grading quizzes wasn’t her favorite activity.
“And so you had the combination memorized,” Hannah said.
“Yes,” Mrs. Ramirez answered. “And it was easy to remember.”
“Did you tell anyone the combination?” Ben asked.
“No,” Mrs. Ramirez said. “But I did tell my students the formula for the combination.”
“Yes, Corey mentioned that,” Ben said. “What was the formula?”
Mrs. Ramirez got up and walked over to the dry-erase board. “Well,” she began, “every year with my homeroom class, I use this formula as a learning exercise.”
She picked up a marker and then wrote “First number = even.”
“The first number in the padlock combination is an even number,” she said.
“Okay,” Ben said, writing in a small notebook he carried with him at all times so he could keep track of clues.
Mrs. Ramirez wrote “Second number = (First number/two) squared” on the board.
“The second number is the first number divided by two and then squared—multiplied by itself,” she explained.
“Got it,” Ben said, writing.
Finally, the teacher wrote “Third number = First number + Second number.”
“The third number is the sum of the first two numbers,” she finished.
“Oh yeah,” Corey said. “I remember this now. I didn’t know the answer the first time, and I don’t know the answer now.”
Corey sometimes thought his brain just wasn’t made the right way to get math. But then he’d look at some NBA player’s stats, and he’d understand them perfectly. So maybe it wasn’t just his brain. Maybe it had something to do with what he was interested in.
“There are several possible correct answers,” Ben said.
“Yes,” Mrs. Ramirez said. “That’s right.”
Hannah carefully looked at what Mrs. Ramirez had written on the board. “It seems to me that the formula would be easy to figure out if you knew one of the numbers,” Hannah noted.
Mrs. Ramirez agreed. “If you were just trying to guess the answer, you’d have to go through quite a few combinations. But if you knew one of the three numbers, you could easily figure out the other two.”
Ben thought for a moment. Then he asked, “What’s the last number?”
Mrs. Ramirez hesitated. “I’ve always kept that information a secret. But I suppose it doesn’t matter now.”
“Now that the thief knows your combination, I guess you’ll have to change it, anyway,” Corey pointed out.
She nodded. “Yes, that’s right. So I might as well tell you three. The last number is 35.”
“So the combination was 10, 25, 35,” Ben said quickly.
Corey’s mouth dropped open. “How did you figure that out so quickly? Did you secretly use a calculator?”
“No,” Ben said. “It’s just algebra. Think of the numbers as X, Y, and Z. Then plug in 35 for Z, and solve for X and Y.”
“I think I’d rather just think of your brain as freakishly big,” Corey said.
Hannah asked Mrs. Ramirez if Ben was right. She nodded. “Absolutely. That’s the correct answer, and the combination that opens the padlock.”
“So Ben was able to figure out the combination once he knew the last number,” Hannah said. “But how would the thief have known any of the numbers?”
“Do you say the numbers to yourself as you turn the dial on the padlock?” Corey asked. “Because maybe the thief could read lips.”
Mrs. Ramirez smiled. “Well, I’m not completely sure, but I don’t think I move my lips as I turn the dial.”
Ben got an idea. “Did you spin the dial after you locked the padlock?”
“You mean when I put the box away on Monday morning?” Mrs. Ramirez asked. Ben nodded. She frowned, trying to remember.
“That’s quite a few days ago now,” she said, thinking. “I can’t really be sure whether I spun the dial or not. Do you remember, Corey?”
Corey thought back to last Monday morning. He vaguely remembered Mrs. Ramirez putting the metal box in her desk drawer after everyone had put their envelopes of money in it, but he didn’t remember whether or not she spun the dial on the padlock.
“I really don’t remember,” Corey said. “She could have spun the dial on the padlock after it was below the top of her desk, so we couldn’t see.”
“I don’t think I would do that,” Mrs. Ramirez said. “Once I picked up the metal box, I would probably hold it in one hand while I opened my desk drawer with my other hand. I wouldn’t have a hand free to spin the dial on the combination lock.”
Ben and Hannah listened to all this and thought about it. “My guess is,” Ben said slowly, “that you didn’t spin the dial on the combination lock after you closed it.”
“So the dial was still set on the combination’s final number, 35,” Hannah added.
“Right,” agreed Ben. “All the thief had to do was look at the dial to see the final number. Then he or she would just have to use the formula to figure out the first two numbers in the combination.”
“Okay,” Corey said. “But that means the thief had to know the formula. And Mrs. Ramirez only tells the formula to the kids in her homeroom. Right?”
Mrs. Ramirez nodded.
“E
xcept the fingerprints already showed us that the thief is probably someone from outside our homeroom,” Corey reminded them.
Ben and Hannah looked stumped for a minute. Then Hannah remembered something. “Mrs. Ramirez, didn’t you say that you use this formula with your homeroom every year?”
“Yes,” she agreed. “I’ve been using it for several years now.”
“I see where you’re going with this, Hannah,” Ben said. “Maybe the thief was in Mrs. Ramirez’s homeroom in a previous year.”
“Right!” Hannah said. “Like last year, so you might still remember the formula. The thief might be an eighth grader.”
“Maybe we should fingerprint all the eighth graders!” Corey said.
Ben held up his hands. “We really just need the kids from Mrs. Ramirez’s homeroom last year, but I think we should run this theory by Miss Hodges before we try to get permission to fingerprint any more students.”
“That sounds like an excellent idea, Ben,” Mrs. Ramirez said.
“Well, what are we waiting for?” Hannah said. “Let’s go!”
She hurried out of the classroom. Ben and Corey followed her. At the door, Corey turned back to
Mrs. Ramirez. “Thanks, Mrs. Ramirez!” he said.
“You’re welcome!” she said, turning back to grading the stack of quizzes with a little sigh.
Hannah, Ben, and Corey got to school extra early the next morning, eager to bounce their latest theory off Miss Hodges before homeroom.
She wasn’t impressed.
“It’s a pretty good theory,” she said. “But it’s not conclusive. I’m afraid it’s never going to convince Principal Inverno to let you get fingerprints from all the eighth graders.”
Hannah and Ben looked disappointed. Secretly, Corey was relieved. He hadn’t been looking forward to pressing all those eighth graders’ fingers onto ink pads and then onto cards. Not to mention having to compare all those fingerprints to the unidentified set of prints they’d taken off the metal box and the desk drawer handle. He felt like his eyes were still tired from the first round of fingerprint comparisons.
“Well,” Ben said, “in that case, it seems as though we’ve hit another dead end. The padlock combination didn’t lead us to the thief.”