With the collapse of the conglomerate, the city gradually returned to its former prosperity and tranquility. Conan, Lin Yu, Ai Haibara, Ran Mouri, and Kogoro Mouri were finally able to temporarily set aside their tension and enjoy this hard-won peace.

Conan returned to school, where his classmates were filled with curiosity and admiration for his heroic deeds.

"Conan, you're amazing! You actually managed to defeat such a bad person!"

"Conan, tell us about your adventures!"

Conan simply smiled at his classmates' enthusiasm. He knew that although the real danger had passed, the mission to protect justice would never end.

Lin Yu received numerous offers from technology companies for his outstanding performance in fighting against conglomerates. However, he was not blinded by fame and fortune. Instead, he chose to join forces with like-minded friends to establish a cybersecurity organization dedicated to protecting the peace and security of the online world.

Ai Haibara threw herself back into medical research, hoping to use her knowledge to help more people escape the suffering caused by illness. Her heart grew stronger and warmer, and the shadows of the past gradually faded.

Ran Mouri has achieved even greater success in the field of karate, and her name is becoming increasingly well-known in the martial arts world. At the same time, she frequently participates in charitable activities, using her influence to contribute to society.

Kogoro Mouri's detective agency is thriving. With his experience and wisdom, he solves one difficult case after another, becoming a legendary figure in the industry.

However, the peaceful days didn't last long. One day, Conan received a mysterious letter. The letter mentioned an ancient treasure legend, said to hold great secrets and power, and that many people were searching for it.

Conan immediately told his friends the news.

"Could this be a trap?" Lin Yu asked with some concern.

Ai Haibara pondered for a moment, "Perhaps, but it could also be a new challenge."

Ran Mouri, however, was full of fighting spirit. "Let's go take a look no matter what."

Kogoro Mouri agreed, saying, "We might make a great discovery."

So they decided to explore this mysterious treasure legend together.

Following the clues provided in the letter, they arrived at a remote town. The town appeared peaceful and serene, but Conan sensed something unusual.

"Everyone be careful, there might be danger lurking here," Conan warned.

They inquired around the town and finally found an old man who knew a clue to the treasure.

The old man looked at them, his eyes filled with wariness. "Why are you looking for this treasure?"

Conan said sincerely, "We're not after the wealth, we just want to unravel the secret."

The old man remained silent for a while, and finally decided to tell them some clues.

Following the old man's directions, they arrived at an ancient castle. The castle had been abandoned for many years and was filled with various mechanisms and puzzles.

“This is a real problem,” Kogoro Mouri said, looking at the complex mechanism.

Conan carefully observed the surroundings. "Everyone, don't panic, let's think of a solution together."

They began working together to crack the mechanisms. Lin Yu used his technical knowledge to find the control mechanisms of some of them; Ai Haibara solved some puzzles by analyzing chemical substances; and Ran Mouri and Kogoro Mouri, with their strength and courage, faced the potential dangers.

In the process of solving the puzzles, they encountered many difficulties and challenges. Sometimes they would accidentally trigger traps, and sometimes they would find themselves in dead ends, but they never gave up.

"I believe we can succeed," Conan encouraged everyone.

After several days of effort, they finally reached the depths of the castle. There, they discovered a huge treasure chest.

Just as they were about to open the treasure chest, a group of mysterious people appeared.

“We found it first, you can’t take it!” said the leader of the mysterious men.

Conan and the others realized that this was yet another new battle.

A fierce battle ensued. Conan used his intelligence to devise ingenious tactics; Lin Yu used his hacking skills to disrupt the enemy's communications; and Ran and Kogoro Mouri displayed their fighting abilities, engaging in close combat with the enemy.

During the intense battle, Conan discovered the mysterious man's weakness.

"Attack their left flank!" Conan shouted.

Following Conan's instructions, everyone quickly gained the upper hand.

In the end, they successfully repelled the mysterious man and opened the treasure chest.

However, the treasure chest did not contain the gold and silver treasures one might expect, but rather an ancient diary.

Conan opened his diary, which contained a tragic story about the castle and its treasure. It turned out that the treasure wasn't wealth, but rather a legacy of wisdom and courage left by the castle's owner to protect the town.

"So this is the true meaning of the treasure," Ai Haibara said with emotion.

Conan and the others returned to the town with the diary and told everyone the story.

From then on, Conan and his friends continued their adventure, using their wisdom and courage to meet one new challenge after another, and to protect world peace and justice.