"That was Shan Fu," said Cao Ren.

"Who is he?" asked Cao Cao.

Cheng Yu said, "The man is not Shan Fu. When young this man was fond of fencing and used to take up the quarrels of other people and avenge their wrongs. At the end of Emperor Ling, he killed a man to avenge his friend, and then he let down his hair, muddled his face, and was trying to escape when a lictor caught him and questioned him. He would not reply. So they carted him through the streets beating a drum and asking if anyone recognized him. Nobody dared own to knowing him, even if they did so. However, his comrades managed to release him secretly, and he ran away under some other name. Then he turned to study and wandered hither and thither wherever scholars were to be found. He was a regular disputant with Sima Hui. His real name is Xu Shu and he comes from Yingchuan. Shan Fu is merely an assumed name."

"How does he compare with yourself?" asked Cao Cao.

"Ten times cleverer."

"It is a pity. If able people gather to Liu Bei, his wings will soon grow. What is to be done?"

"Xu Shu is there now. But if you wanted him, it would not be difficult to call him," replied Cheng Yu. "How could I make him come?" said Cao Cao.

"He is noted for his affection for his mother. His father died young, leaving his mother a widow with one other son. Now that son is dead, and his mother, Lady Xun, has no one to care for her. If you sent and got his mother here and told her to write and summon her son, he would surely come."
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She was given quarters and cared for. Daily Cheng Yu went to ask after her health, falsely claiming to being a sworn brother of her son's, and so entitled to serve her and treat her as a filial son would have done. He often sent her gifts and wrote letters to her so that she had to write in reply. And thereby he learned her handwriting so that he could forge a "home" letter. When he could do this without fear of detection, he wrote one and sent it by the hand of a trusty person to Xinye.