In a mysterious and fantastical world, the atmosphere of Halloween is always exceptionally intense. A gloomy castle stands quietly in the wilderness. The ancient walls are covered with vines, and the windows are broken and tattered, as if telling the vicissitudes of time. The Halloween decorations make this castle extremely terrifying. Huge pumpkin lanterns flicker with eerie lights, black bats fly in the night sky, and white ghost flags flutter in the wind.

On this mysterious night filled with an air of mystery, Zhang Guolao rode his donkey slowly and arrived outside this castle. Zhang Guolao was dressed in a Taoist robe, with white hair and a kind face. His donkey had black fur, bright eyes, and its hooves made a crisp sound as they stepped on the ground. The donkey's braying echoed in the silent night sky, attracting the attention of the ghosts in the castle.

The ghosts in the castle were originally drifting and wandering in the darkness. They were startled by this sudden sound. They all stopped and looked in the direction of the sound. They saw a strange old man and a donkey appear outside the castle. Their hearts were filled with doubts and vigilance. The ghosts didn't know who this old man was or what his purpose was in coming here.

Zhang Guolao unhurriedly took out some magical herbs from his pocket. These herbs emitted a wafting fragrance. That aroma was like the first ray of sunlight in the morning, warm and fresh. The ghosts were attracted by this fragrance and gathered around one after another. They looked curiously at the herbs in Zhang Guolao's hands, their hearts full of curiosity.

Zhang Guolao looked at these ghosts and said with a smile, "Children, don't be afraid. These herbs are brought by me from the East. They have magical effects." After hearing Zhang Guolao's words, the vigilance in the ghosts' hearts gradually subsided. They looked at Zhang Guolao, waiting for his further explanation.

Zhang Guolao began to tell the ghosts about the health preservation methods of Taoism in the East. He told the ghosts that Taoism pays attention to the balance and harmony of body and mind. Through cultivation and health preservation, one can reach the realm of prolonging life and transcending the mundane. Zhang Guolao recounted the cultivation methods of Taoism, such as meditation, breath regulation, and dietary health preservation. He also introduced some magical herbs and exercises, making the ghosts full of longing for the mysterious power of the East.

The ghosts were mesmerized. They seemed to enter a whole new world. In this world, there is no death or fear, only the vitality of life and mysterious power. They were deeply attracted by Zhang Guolao's story, and their hearts were full of curiosity and longing for Taoism in the East.

Zhang Guolao looked at the ghosts' reactions and felt extremely gratified in his heart. He knew that although these ghosts lived in the darkness, their hearts still longed for light and hope. So, he decided to continue telling them stories about Taoism and let them know more about the knowledge of the mysterious power of the East.

Zhang Guolao recounted the origin and development of Taoism and told the thoughts and concepts of Taoism. He told the ghosts that Taoism emphasizes following nature, respecting life, and pursuing truth. Taoism believes that everything in the world has its own laws. Only by following nature can one obtain true happiness and tranquility.

The ghosts listened quietly to Zhang Guolao's narration. Their hearts were full of thoughts. They began to reflect on their own lives and think about the meaning and value of life. They realized that although they had died, their souls could still obtain a higher realm and a deeper understanding through cultivation and learning.

Under the influence of Zhang Guolao, the ghosts in the castle began to change their way of life. They no longer indulged in fear and darkness but began to explore the mysteries of life and mysterious power. They learned the health preservation methods of Taoism and cultivated their bodies and minds, hoping to find true happiness and tranquility in the world of souls.

And Zhang Guolao also felt the kindness and longing of these ghosts in getting along with them. He knew that although these ghosts had left the world of the living, their souls still had infinite possibilities. He decided to stay outside this castle and help these ghosts find their own direction and goal.

On this mysterious and fantastical Halloween night, the story of Zhang Guolao and the castle ghosts has become a beautiful legend. It will be passed down forever, inspiring everyone to bravely explore the mysteries of life and pursue the light and hope in their hearts.

As time passed, the night of Halloween gradually passed, and the eastern sky turned fish-belly white. Zhang Guolao looked at the ghosts in the castle, smiled and waved his hand, then rode his donkey and left. The ghosts looked at Zhang Guolao's departing back, their hearts full of reluctance. They knew that although Zhang Guolao had left, the story and spirit he left behind would always accompany them.

Since then, every year on Halloween night, the ghosts in the castle will recall the story of Zhang Guolao. They will tell this story to other ghosts, so that more ghosts can understand the mysterious power of Taoism in the East. And Zhang Guolao has also become an idol in their hearts, inspiring them to keep moving forward and explore the mysteries of life.

In this world full of love and hope, the story of Zhang Guolao and the castle ghosts will always shine. It will become a guiding light in people's hearts, illuminating people's way forward and allowing people to find true happiness and tranquility on the journey of life.