Zhuge Liang put the Wei soldiers who had come over to his side in one of the rear divisions. With their dress and arms, he disguised five thousand of his own troops so that they looked like his enemies, and then he sent this division — under Guan Xing, Liao Hua, Wu Yi, and Wu Ban — to raid Cao Zhen's camp. Before they reached the camp, they sent one of their number ahead as a galloper to tell Cao Zhen that there had been only a few men of Shu and they had all been chased out of sight, and so lull him into security.
This news satisfied Cao Zhen. But just then a trusty messenger from Sima Yi came with a message: “Our troops have fallen into an ambush, and many have been killed. Do not think any more about the wager: that is canceled. But take most careful precautions.”
“But there is not a single soldier of Shu near,” said Cao Zhen.
He told the messenger to go back. Just then they told him Qin Liang's army had returned, and he went out to meet them. Just as he got near, someone remarked that some torches had flared up in the rear of his camp. He hastened thither to see. As soon as he was out of sight, the four leaders waved on their troops and dashed up to the camp. At the same time Ma Dai and Wang Ping came up behind, and Ma Zhong and Zhang Yi came out.
The soldiers of Wei were trapped and helpless; they scattered and fled for life. Cao Zhen, protected by his generals, fled away to the eastward. The enemy chased them closely. As Cao Zhen fled there arose a great shouting, and up came an army at full speed. Cao Zhen thought all was lost, and his heart sank, but it was Sima Yi, who drove off the pursuers.
Though Cao Zhen was saved, he was almost too ashamed to show his face.
Then said Sima Yi, “Zhuge Liang has seized Qishan, and we cannot remain here; let us go to River Wei, whence we may try to recover our lost ground.”
“How did you know I was in danger of defeat?” asked Cao Zhen.
“My messenger told me that you said there was not a single soldier of Shu near, and I knew Zhuge Liang would try to seize your camp. So I came to your help. The enemy's plan succeeded, but we will say no more about that wager. We must both do our best for the country.”
But the fright and excitement made Cao Zhen ill, and he took to his bed. And while the army were in such a state of disorder, Sima Yi was afraid to advise a return. They camped at River Wei.
After this adventure Zhuge Liang hastened back to Qishan. After the soldiers had been feasted and services recognized, the four discontented leaders — Wei Yan, Chen Shi, Du Qiong, and Zhang Ni — came to the tent to apologize.
“Who caused the loss?” said Zhuge Liang.
Wei Yan said, “Chen Shi disobeyed orders and rushed into the valley.”
“Wei Yan told me to,” said Chen Shi.
“Would you still try to drag him down after he rescued you?” said Zhuge Liang. “However, when orders have been disobeyed, it is useless to try and gloze it over.”
Zhuge Liang sentenced Chen Shi to death, and he was led away. Soon they brought his head into the presence of the assembled generals. Wei Yan was spared as there was yet work for him to accomplish.
After this, Zhuge Liang prepared to advance. The scouts reported that Cao Zhen was ill, but was being treated by doctors in his tent.
The news pleased Zhuge Liang, and he said to his officers, “If Cao Zhen's illness is slight, they will surely return to Changan. They must be delayed by his serious sickness. He stays on so that his soldiers may not lose heart. Now I will write him such a letter that he will die.”
Then he called up the soldiers of Wei who had yielded, and said to them, “You are Wei troops, and your families are all over there: it is wrong for you to serve me. Suppose I let you go home?”
They thanked him, falling prostrate and weeping.
Then Zhuge Liang continued, “Friend Cao Zhen and I have a compact, and I have a letter for him which you shall take. The bearer will be well rewarded.”
They received the letter and ran home to their own tents, where they gave their Commander-in-Chief the letter. Cao Zhen was too ill to rise, but he opened the cover and read:
“You will permit me to say that a leader of an army should be able to go and come, to be facile and obdurate, to advance and retire, to show himself weak or strong, to be immovable as mountains, to be inscrutable as the operations of nature, to be infinite as the universe, to be everlasting as the blue void, to be vast as the ocean, to be dazzling as the lights of heaven, to foresee droughts and floods, to know the nature of the ground, to understand the possibilities of battle arrays, to conjecture the excellencies and defects of the enemy.
