Long ago, there were a dozen or so families living at the foot of Longshan Mountain. There was an old man named You Bu who loved to play chess. He had two daughters and a son, You Yun, who was still unmarried. The family worked hard and lived a decent life.
One summer, You Bu went to the mountain to repair trees. It was hot and dry, and he soon became thirsty, tired, and hungry. He saw two old men playing chess under a big locust tree, with a teapot and two bowls beside them. He approached them and started chatting. As he often played chess with others at home, he was familiar with the game and even gave them some advice. The two old men were kind to him and offered him a bowl of tea. After drinking it, You Bu felt a refreshing sensation rising from his stomach, relieving his fatigue and thirst. He even dozed off while watching the chess game.
When he woke up, the two old men were still playing chess. You Bu found it strange and couldn't understand the game anymore. He realized that his son You Yun was going to Jining Prefecture the next day, so he said goodbye to the old men and hurried down the mountain.
However, he found that the path was different from before and the people in the village were all strangers to him. He couldn't find his home or his son. A white-bearded old man told him that he was You Bu, a ninety-three-year-old man who had lived in the village for generations. He also said that You Yun was his ancestor's ancestor. You Bu was shocked and went back to the mountain to find the two old men who played chess with him, but he couldn't find them or the big locust tree. He cried for days until he fell asleep.
In his sleep, an old man told him to stop crying and gave him a sword, saying he should do good things for humanity. When You Bu woke up, he found the sword next to him. He followed the old man's advice and did good deeds for many years, helping to bring peace and justice to the land. Eventually, he was summoned by the Jade Emperor to the heavens. People named the cave where he cried "Lao You Dong" to commemorate him.