When he heard that the army of Wei had camped in Beiyuan, he said to his officers, “They camp there fearing that our holding this area will sever connection with Xizhou. I am pretending to look toward Beiyuan, but really my objective is River Wei. I am going to build several large rafts and pile them with straw, and I have five thousand of marines to manage them. In the darkness of the night I shall attack Beiyuan; Sima Yi will come to the rescue. If he is only a little worsted, I shall cross the river with the rear divisions. Then the leading divisions will embark on the rafts, drop down the river, set fire to the floating bridges, and attack the rear of the enemy. I shall lead an army to take the gates of the first camp. If we can get the south bank of the river, the campaign will become simple.”
Then the generals took orders and went to prepare.
The spies carried information of the doings of the troops of Shu to Sima Yi, who said to his generals, “Zhuge Liang has some crafty scheme, but I think I know it. He proposes to make a show of taking Beiyuan, and then, dropping down the river, he will try to burn our bridges, throw our rear into confusion, and then attack our camps.”
So he gave Xiahou Ba and Xiahou Wei orders: “You are to listen for the sounds of battle about Beiyuan; if you hear the shouting, you are to march down to the river, to the hills on the south, and lay an ambush against the troops of Shu as they arrive.”
Zhang Hu and Yue Chen were to lead two other forces, of two thousand of bowmen each, and lie in hiding on the north bank near the bridges to keep off the rafts that might come down on the current and keep them from touching the bridges.
Then he sent for Guo Huai and Sun Li, and said, “Zhuge Liang is coming to Beiyuan to cross the river secretly. Your force is small, and you can hide half way along the road. If the enemy cross the river in the afternoon, that will mean an attack on us in the evening. Then you are to simulate defeat and run. They will pursue. You can shoot with all your energy, and our marines and land troops will attack at once. If the attack is in great force, look out for orders.”
All these orders given, Sima Yi sent his two sons Sima Shi and Sima Zhao to reinforce the front camp, while he led his own army to relieve Beiyuan.
Zhuge Liang sent Wei Yan and Ma Dai to cross River Wei and attack Beiyuan, while the attempt to set fire to the bridges was confided to Wu Ban and Wu Yi. The general attack on the Wei camp by River Wei was to be made by three divisions: the front division under Wang Ping and Zhang Ni, the middle division under Jiang Wei and Ma Zhong, the rear division under Liao Hua and Zhang Yi. The various divisions started at noon and crossed the river, where they slowly formed up in battle order.
Wei Yan and Ma Dai arrived Beiyuan about dusk. The scouts having informed the defenders of their approach, Sun Li abandoned his camp and fled. This told Wei Yan that his attack was expected, and he turned to retire. At this moment a great shouting was heard, and there appeared two bodies of the enemy under Sima Yi and Guo Huai bearing down upon the attackers. Desperate efforts were made to extricate themselves, but many of the soldiers of Shu fell into the river and drowned. The others scattered. However, Wu Yi came up and rescued the force from entire destruction.
Wu Ban set half his troops to navigate the rafts down the river to the bridges. But Zhang Hu and Yue Chen stationed near the bridges shot clouds of arrows at them, and the Shu leader, Wu Ban, was wounded. He fell into the river and was drowned. The crews of the rafts jumped into the water and got away. The rafts fell into the hands of the soldiers of Wei.
At this time the front division under Wang Ping and Zhang Ni were ignorant of the defeat of their Beiyuan army, and they went straight for the camps of Wei. They arrived in the second watch.
They heard loud shouting, and Wang Ping said to Zhang Ni, “We do not know whether the cavalry sent to Beiyuan has been successful or not. It is strange that we do not see a single soldier of the enemy. Surely Sima Yi has found out the plan and prepared to frustrate the attack. Let us wait here till the bridges have been set on fire and we see the flames.”
So they halted. Soon after, a mounted messenger came up with orders: “The Prime Minister bade you retire immediately, as the attack on the bridges has failed.”
Wang Ping and Zhang Ni attempted to withdraw, but a bomb exploded and the troops of Wei, who had taken a by-road to their rear, at once attacked. A great fire started also. A disorderly battle ensued, from which Wang Ping and Zhang Ni eventually forced their ways out, but only with great loss.
And when Zhuge Liang collected his army at Qishan once more he found, to his sorrow, that he had lost more than ten thousand troops.
Just at this time Fei Yi arrived front Chengdu.
