It was early morning when Mackenzie woke up. After getting dressed, she stepped into the hallway and encountered her brother, Mason, before heading downstairs for breakfast. "Good morning," he said. "Are you going to the theater today? Do you think Mom and Dad might consider letting me join?" 

"I'm afraid not," Mackenzie replied. "You know there's no way Mom and Dad are going to lift your punishment just so you can go to a movie." They both descended the stairs to the dining room, where their parents were already seated at the table. 

"Good morning, kids," their dad greeted them. "Enjoy the movies today, Mackenzie," their mom added. 

"Thanks! By the way, Mason was hoping you'd reconsider his punishment so he could join us too," Mackenzie mentioned. 

"Sorry, son," their dad replied, "but you know the rules. All punishments are final, no exceptions." Mason's face fell with disappointment. 

"Please, Dad, just this once," he pleaded. 

"Sorry, Mason," their mom said gently. "But rules are rules. When you break them, there are consequences. So perhaps next time you'll think twice before sneaking into the teachers' lounge." 

As Mackenzie left, she bid farewell to her parents and brother, eager to meet her friend, Alicia, who was waiting by the front door. 

"Hey, Mackenzie!" Alicia exclaimed, her excitement palpable. "Is Mason not coming?" 

"Mason is grounded for sneaking into the teachers' lounge, so he won't be able to join us today. I'll fill you in on the details on our way to the theater." 

As they began walking, Mackenzie recounted how Mason had decided to sneak into the teachers' lounge while they were working on a case, hoping to find clues when he thought no one would be around—but he got caught instead. She also explained that, as a result, their parents grounded him for a month once they discovered what he had done.

"A whole month? He's grounded for that long?" asked Alicia.

"Oh yeah," said Mackenzie. "Our parents are very strict when it comes to punishment; they won't let anything slide."

As they started coming up to the theater, Mackenzie stopped talking as she saw the owner in distress.

"Is everything alright, Mr. Monroe?" Mackenzie asked.

"Mackenzie! Oh thank goodness you're here. We've got a big problem. We've got a big premiere tonight, and everything from the concession stand is gone," the girls both looked at each other in confusion. "What do you mean everything is gone?" asked Mackenzie as the girls followed Mr. Monroe.

As soon as they entered the theater, they saw that everything was completely empty.

"See? It's all gone. Someone stole it all."

"Are you absolutely sure it was stolen?" asked Mackenzie. "Did you check the surveillance cams? It might lead to a clue as to who's behind this."

"Yes," said Mr. Monroe. "I checked the cams but found nothing. Don't worry, Mr. Monroe. The Mystery Twins are on the case," said Mackenzie.

"Uh, Mackenzie," Alicia said confused, "we're not twins."

"I know, but it's our official trademark, and I just like saying it," said Mackenzie. 

"Mr. Monroe, do you happen to know the exact time that everything was stolen?" asked Mackenzie.

Mr. Monroe thought for a moment. "I remember working late last night until about 10:00 pm. By the time I locked up, everything was still here. It wasn't until I came in this morning that I noticed everything was gone."

Was there anyone else still in the building after you left?" asked Mackenzie.

"The only people who would still be in the building are the cleaners and the closing ushers," said Mr. Monroe.

"We're going to need the names of everyone who had access to the building during the night shift, and we're going to have to talk to them. In the meantime, I think we should look for any clues the culprit may have left behind," said Alicia.

So, the girls began to spread out and search the area, even checking the door for signs of a break-in, of which there were none. Therefore, it had to have been an inside job. They searched everywhere they could look for clues but couldn’t find anything.

"Whoever's behind this really went all out to cover their tracks," said Alicia.

"It looks like the staff is starting to come in, so now would be a good time to ask them some questions," said Mackenzie.

Just as Mackenzie was about to interview the first witness, she heard a noise coming from the back room. Thinking that it might lead her to the culprit, she decided to go check it out, only to find that Mason had snuck out.

"What are you doing here?" she whispered angrily. "You're supposed to be grounded."

"I know," said Mason quietly. "I snuck out of my bedroom window."

"When Mom and Dad find out you're gone, you're going to get much more than just grounded. You know how they are," Mackenzie said in frustration. "You need to get back home now before you get into even more trouble than you already are."

"What are you doing?" asked Mason. "I thought you and Alicia were watching a movie.

Mackenzie said, "Things got complicated. We're in the middle of solving a case right now, and I don't have time to explain all of the details. The short explanation is that everything from the snack bar was stolen, and we're trying to figure out who might've done it. I was just about to question the staff for any leads."

Noticing that Mackenzie had been gone for a long time, Alicia walked in to see what was taking her so long. "Mason, what are you doing here? You're supposed to be grounded," Alicia added, echoing Mackenzie's earlier concern.

"Yeah, I know," Mason repeated, gathering his courage. "But you guys need my help. I think I saw something when I snuck out, something important." Mackenzie narrowed her eyes, skeptical but intrigued. "Alright, spill it, Mason. What did you see?"

Mason took a deep breath, glancing around to ensure they were alone. "I saw someone leaving the snack bar late last night, after it was supposed to be closed," Mason confessed.

"Did you see who it was?" asked Mackenzie.

"I never saw his face, and I didn't see where he went," said Mason. "If you ask me, the owner should be our prime suspect. He's the only one who has access to the building. No one else has a key to the building."

"But we don't have any evidence to prove that," Mackenzie replied.

"He could have hired someone or left a door unlocked to let them in," Mason suggested, trying to think like a detective.

"That's possible," Mackenzie admitted, "but we need solid evidence if we want to accuse anyone."

"We'll have to review the security footage first," Mason said, determined.

"Let's head to the control room," Mackenzie replied, already moving toward the door.

The pair hurried down the corridor, their footsteps echoing in unison. As they approached the control room, Alicia whispered, "What if the footage was tampered with?"

"I don’t see any evidence of sabotage," said Mackenzie. "Mr. Monroe is the only one who would have access to the control room, but he said he checked and didn’t see anything."

"Something's not adding up here," said Mackenzie. "Let's go back and talk to the staff to see if they know or saw anything."

As soon as they were about to leave the control room, Mackenzie spotted something strange going on outside. Someone was standing behind a giant truck outside the theater.

"Who is that?" Mason asked in a whisper.

"It looks like Mr. Monroe, but what’s he doing with that truck? Think maybe it could be a supply order?" asked Alicia.

"If it were, he wouldn’t be loading it," said Mackenzie. "I think we need to follow him."

The three detectives hid inside the truck, careful not to get caught, until they came to a big warehouse in the city. 

"What are all of these boxes for?" asked Mason.

"Wait a minute, this is all of the candy from the theater, and not just one theater, but a whole bunch of them," Mackenzie said quietly. "But what I don’t understand is why he would ask us to look into the case if he was the one behind it."

"It’s quite simple," said Mr. Monroe. "It was all so I could lure you into a trap, and what better way than to set up a fake mystery for you to solve? There is no big premiere at the theater; that was a lie to get you to investigate. Isn’t that right, Alicia?"

"Alicia? You were in on this the whole time?" Mackenzie asked in disbelief.

"Of course," said Alicia. "I was the one who took everything from the snack bar to begin with."

"So that was you I saw last night when the theater was closed!" Mason shouted.

"Yep," said Mr. Monroe. "Alicia removed the snacks from the snack bar so you would have a reason to investigate. All of these boxes contain nothing but billions of dollars in cash that I stole from every theater; that's going to buy me a brand new luxury house in the Bahamas."

"You'll never get away with this," shouted Mackenzie.

"Oh yeah?" said Mr. Monroe. "Who are you going to call, your parents? Your brother is supposed to be grounded, remember? As a matter of fact, my parents and the cops should be arriving shortly," said Mackenzie. "They were listening the whole time; you just didn’t know it."

"Looks like the only vacationing you’ll be doing will be behind bars, you and your accomplice," said Mason as their parents and the police arrive to take Mr. Monroe and Alicia away.

"Hello, kids," said their dad with an angry look on his face.

"Hehe, hi," said Mason with a guilty look.

"We’ll talk about your sneaking out later, young man, but right now, we need to get these two into custody. Nice detective work, guys."

Back at home, the whole family gathered around the living room for a family discussion.

"Ok, look, I’m sorry I snuck out, but Mackenzie needed me, and I couldn’t let her down. I’m ready to take whatever punishment you throw at me."

Both parents gave each other a look, then looked at Mason in disappointment.

"Look, son," said their mom, "we’re very proud of you for feeling the need to go help your sister, even though she can handle herself on her own, but you still snuck out when you were supposed to be grounded, and that we can’t ignore. So, your grounding is being extended by another month, understood?"

"Yes, ma’am," said Mason.

"Now, it's time for both of you to get upstairs and start getting ready for bed," said their dad.

The twins both started heading upstairs after a long day, to start getting ready for bed.

"Wow," said Mackenzie, "I would say they let you off easy, but don’t get used to it."

Before they could go into their rooms and go to bed, Mason stopped to ask one last question.

"There’s still one thing I don’t understand, though. We know what Mr. Monroe was planning to do with all of that cash, but what did Alicia gain from helping him?"

Mackenzie thought for a moment. "I guess there are some questions that just aren’t meant to be answered."

And with that, they entered their rooms and went to bed.