Masud stood in the eerie silence of the school hallway, eyeing the QR code on the poster. The corners of his lips curled into a smirk; this was the kind of puzzle he loved to solve.

"Hey, Masud! What's that?" A voice echoed down the hallway. It was his friend, Ravi, always tagging along and eager to join in on the mystery-solving.

"It's a QR code, Ravi," $$C_ENC_1$$ replied, scanning it with his smartphone. As the scanned information appeared on his screen, he let out a gasp. This was no ordinary message.

Masud showed the mysterious message to Ravi. The message was a series of numbers and letters, looking like a code. "Let's give this a shot!" Ravi declared enthusiastically.

Together, they started deciphering the code, comparing it against symbols and patterns in their textbooks set it to a strange code. The school day ended, but the mystery did not.

The next day, they discovered a missing globe from the geography room. Strangely enough, another QR code was stuck on the table where the globe previously sat.

As days passed, more items disappeared and more QR codes appeared. The boys' curiosities turned into worry. They realized something was about to take place, and they needed to prevent it.

Masud decided they needed more help and recruited another friend, Nina, a tech whizz, who was always up for a challenge.

With Nina on board, they were able to decipher the codes faster. The messages hinted at a mysterious event that was set to take place in a week.

They decided to split up and gather more information. While Ravi talked to the students, Masud investigated the missing items, and Nina cracked the codes.

Ravi discovered rumors about a 'grand event' being planned by some students. While not much was known, it was clear something was happening soon.

On the other hand, Masud mapped the missing objects' locations. He realized they formed a path leading to the old school library.

Nina managed to crack a major part of the code. It revealed the date and time of the event, which coincided with the school's annual cultural night.

The trio decided to investigate the library after school. Sweating in the summer heat, they went through the massive wooden doors into the dusty old library.

They discovered another QR code inside an ancient geography book. When they scanned it, it led them to a secret door in the library.

Behind the secret door was a hidden room filled with all the missing objects. It was a planned scavenger hunt by the school's event committee for the cultural night.

The friends were relieved but also a bit disappointed. Their grand mystery was just a well-planned school event. However, they were proud; they had solved the mystery before anyone else.

On the night of the cultural event, everyone marvelled at the clever scavenger hunt. The event was a massive success, and the trio became local heroes.

From that day forward, Masud, Ravi and Nina became known as the 'Detective Trio' of their school. The adventure was over, but it seemed the school year had just started for the budding detectives.

What started as a mysterious QR code turned into an adventure. Through their exciting journey, the friends learned about teamwork, problem-solving, and the joy of solving a mystery.

That year was filled with many more mysteries for the Detective Trio to solve, but this first case was always the one they remembered the most fondly. It was the beginning of their detective adventures.

As the young detectives grew older, they honed their skills and continued to solve mysteries. Little did the school know, they had their very own Sherlock Holmes, Watson, and Irene Adler among them.

Masud, Ravi, and Nina always stayed friends, their bond strengthened by their shared adventures. The QR code mystery was just the start of many more to come.

As graduation approached, the trio decided to bury a time capsule with their best detective memories, including the first mysterious QR code. It was a perfect end to their high school detective chapter.

Even years later, as they followed different paths, they never forgot their detective adventures. And whenever they saw a QR code, they would always remember their first mystery and smile.