A gust of wind blew softly through the cracks of the window. It was a peaceful night. In the room, a girl laid in her bed, sleeping so deeply that she seemed almost unconscious. Her little brother, a mischievous twinkle in his eyes, approached her cautiously.

He had always been fascinated by his sister's ability to sleep so soundly. Today, he decided to test her limits. With a mischievous smile, he slowly lifted the blanket from her belly.

His intentions were not harmful, just playful. He had always wanted to give his sister belly punches, a harmless game they used to play when they were younger.

He raised his small fist, ready to land the first punch. But as he looked down at his sister's belly, he noticed something strange. Her skin was glowing faintly.

His heart pounded in his chest. He had never seen anything like this before. He bent down, his eyes wide with curiosity and a little fear.

The glow was soft, like that of a firefly. It was mesmerizing. The boy extended his hand, wanting to touch the glow, but he hesitated.

And then, the glow started to form patterns. They were complicated, like symbols from an ancient language. He gasped, pulling his hand back.

His mind was racing. He couldn't understand what was happening. He wanted to wake his sister up, but he remembered she couldn't be woken.

He felt lost and scared. He didn't know what to do. He decided to fetch his parents, hoping they could explain this strange phenomenon.

But as he turned to leave, the symbols started to move. They formed a circle around his sister's belly and then started to spin. He froze in place, watching the spectacle.

Suddenly, the circle stopped spinning, and a symbol in the center lit up. It was a symbol he recognized from one of his sister's books. It was the symbol of protection.

The glow started to fade. The symbols disappeared one by one, until only the protection symbol was left. And then, it too, faded away.

He was left standing there, in the silence of the night, his heart pounding in his chest. He looked at his sister, who was still sleeping peacefully.

He decided not to tell his parents about what happened. He knew they wouldn't believe him. He quietly returned to his bed, the image of the glowing symbols still fresh in his mind.

The next morning, his sister woke up as usual. She was oblivious to the strange events of the previous night. The boy, however, couldn't forget what he had witnessed.

He was filled with questions. What were those symbols? Why were they on his sister's belly? And why did they form the symbol of protection?

He decided to investigate. He spent hours pouring over his sister's books, searching for answers. He found nothing that could explain what he had seen.

Days turned into weeks, and weeks into months. The boy never saw the glowing symbols again. But he never stopped looking for answers.

One day, he came across an old book in the library. It was a book about ancient civilizations and their beliefs. He found a chapter about protective symbols.

It said that in some ancient cultures, people believed in protective symbols. They were used to protect the bearer from harm. He remembered the symbol on his sister's belly.

It was the same symbol. He felt a chill run down his spine. His sister was protected by an ancient symbol. But from what?

He couldn't find any more information. He was left with more questions than answers. He decided to keep his discovery a secret, for his sister's sake.

He never told anyone about what he saw that night. His sister continued to sleep peacefully, oblivious to the ancient symbol that once glowed on her belly.

But the boy knew. And he made a promise to himself. He would protect his sister, just like the symbol did. No matter what.

The mystery of the glowing symbols remained unsolved. But the boy was okay with it. Because he knew that his sister was safe. And that's all that mattered to him.

As he grew up, he never forgot about that night. It became a part of him, a secret he carried in his heart. It was a reminder of his promise, his duty as a brother.

And so, the story of the sleeping sister and her protective symbol became a legend in his mind. A legend he would carry with him, always reminding him of his promise.

And even though he never understood the mystery completely, he was content. For he knew that sometimes, mysteries are meant to be unsolved. And sometimes, they're meant to protect us.

In the end, it didn't matter why the symbols appeared or what they meant. What mattered was that his sister was safe. And as long as she was safe, he was happy.

And so, the boy grew up carrying this secret. And the girl slept peacefully, protected by an unseen force. This was their story, a story of brotherly love, protection, and an unsolved mystery.