〃That is because the Qiangs have attacked；〃 said Guo Huai gleefully； and the two made ready to pursue。
They saw ahead of them the army of Shu seemed to be in confusion。 The Van Leader Cao Zun led the pursuit。
Suddenly； as he pressed on； there came a roll of drums； followed by the appearance of a cohort led by Wei Yan； who cried； 〃Stop！ You rebels！〃
But Cao Zun did not obey the summons。 He dashed forward to meet the attack。 He was killed in the third encounter。 His colleague Zhu Zan in similar fashion fell in with a cohort under Zhao Yun； to whose long spear he soon fell victim。 The loss of these two made Cao Zhen and Guo Huai hesitate； and they made to retire。
But before they could face about； they heard the drums of an army in their rear； and Guan Xing and Zhang Bao came out and surrounded them。 Cao Zhen and Guo Huai made a stand for a time； but were soon worsted and fled。 The army of Shu pursued the beaten enemy to the bank of River Wei； where they took possession of the Wei camp。
Cao Zhen was greatly chagrined at his defeat and sad at the loss of his generals。 He send a report of his misfortune to his master and asked for reinforcements。
At the court of Wei one of the ministers told the story； saying； 〃Cao Zhen has been defeated repeatedly； and his two Van Leaders were slain。 Further； his Qiang allies have suffered great loss。 Cao Zhen is sending for help； and the case is very urgent。〃
Cao Rui was alarmed and asked for someone to say how to drive off the victorious foe。
Thereupon Hua Xin said； 〃It will be necessary for Your Majesty to go in person。 You should call together all the nobles； and each will have to exert himself。 Unless this is done； Capital Changan will be lost and the whole Land Within the Passes be in danger。〃
But Imperial Guardian Zhong Yao opposed him。
Said he； 〃The knowledge of every leader must exceed that of those led； then only will he be able to control them。 Sun Zi the Strategist sums it up very briefly： 'Know the enemy； know thyself； and every battle is a victory。' I know Cao Zhen has had great experience in the field； but he is no match for Zhuge Liang。 Still there is such a match； and I will pledge my whole family that he will succeed。 But Your Majesty may be unwilling to listen to me。〃
The Ruler of Wei replied； 〃You are a minister of high rank and old。 If you know any wise person able to repel these soldiers of Shu； call him without delay and ease my mind。〃
Then said Zhong Yao； 〃When Zhuge Liang decided to invade us； he was afraid of the one man I will name。 Wherefore he spread calumnies concerning him； raising suspicion in Your Majesty's mind that you might dismiss him。 That done； Zhuge Liang invaded。 Now employ this man again； and the enemy will retire。〃
〃Who is it？〃 asked the Ruler of Wei。
〃I mean the Imperial mander of the Flying Cavalry； Sima Yi。〃
〃I have long regretted my action；〃 said Cao Rui。 〃Where now is friend Sima Yi？〃
〃He is at the city of Wancheng； idle。〃
An edict was prepared recalling Sima Yi and restoring him to his rank and titles； and conferring upon him the new title mander…in…Chief of the Western Forces and General Who Pacifies the West。 All troops of Nanyang were set in motion； and Cao Rui led them to Changan。 At the same time Cao Rui ordered Sima Yi to be there to meet him on a certain day。 And the orders were sent by a swift messenger to the city of Wancheng。
At this time Zhuge Liang greatly rejoiced at the success he had had。 He was at Qishan； busy with plans for other victories； when Li Yan； who was in mand at the Palace of Eternal Peace； sent his son Li Teng to the camp。 Zhuge Liang concluded that such a visit could only mean that Wu had invaded them； and he was in consequence cast down。 However； he summoned Li Teng to his tent； and when asked the object of his mission； Li Teng replied that he had joyful news to impart。
〃What is your joyful news？〃 said Zhuge Liang。
〃Formerly Meng Da deserted to Wei； but only because he could do nothing else。 Cao Pi thought much of his capabilities； treated him most generously； kept him at his side； gave him titles of General Who Establishes Strong Arms and Lord of Pingyang； and appointed him to the posts of Governor of Xincheng and mander of Shangyong and Jincheng； and so on。 But when Cao Pi died； all was changed。 In Cao Rui's court were many who were jealous of Meng Da's influence and power； so that he enjoyed no peace。
〃He used to talk about being originally one of the Shu leaders； and he was forced to do so…and…so。 Lately he has sent several confidants with letters to my father asking that he would state his case to you as to the happenings。 When the five armies came upon Shu； he wanted to rejoin the River Lands。 Now he is at Xincheng； and； hearing you are attacking Wei； he proposes to lead the army of the three counties about Xincheng； Jincheng； and Shangyong to attack Luoyang while you attack Changan； whereby both capitals will be taken。 I have brought with me his messenger and his letters。〃
This was good news； and the bearer was fittingly rewarded。 But at that moment came the news that Cao Rui was leading an army to Changan and had recalled the banished Sima Yi to office。 This piece of bad news saddened Zhuge Liang not a little。
He told Ma Su； who said； 〃Cao Rui should not be your worry。 If he goes to Changan； we will march there and capture him on the road； and there will be an end of him。〃
〃Do you think I fear him？〃 said Zhuge Liang bitterly。 〃But the recall of Sima Yi is another matter； that troubles me。 And Meng Da's proposal will avail nothing if he es across this man。 Meng Da is no match for him。 He will he captured； and； if he should be； the Middle Land will be hard to conquer。〃
〃Why not put Meng Da on his guard then？〃 said Ma Su。
Zhuge Liang decided to write； and the letter was dispatched immediately。
Meng Da was then at Xincheng； anxiously expecting the return of his last confidential messenger； when； one day； the man returned and gave him this letter from Zhuge Liang himself：
〃Your last letter has convinced me of your loyal rectitude； and I still remember with joy our old friendship。 If your plan succeeds； you will certainly stand in the first rank of most worthy ministers。 But I scarcely need impress upon you the extreme necessity for most perfect secrecy。 Be very careful whom you trust。 Fear everyone； guard against everyone。 This news of the recall of Sima Yi and the proposed junction of armies at Changan is very serious。 If a word reaches Sima Yi； he will e to you first。 Therefore take every precaution and do not regard this as a matter of unimportance。〃
〃They say Zhuge Liang leaves nothing to chance；〃 said Meng Da； smiling as he read。 〃This proves it。〃
He lost no time in preparing a reply； which he sent also by a trusty messenger。 This letter was like this：
〃I acknowledge your most valuable advice； but is it possible that I should be remiss？ For my part I do not think the Sima Yi's affair need cause anxiety； for Wancheng is three hundred miles from Luoyang and four hundred miles from Xincheng。 Should he hear anything； it would take a month to send a memorial to the capital and get a reply。 My ramparts here are strong and my forces posted in the best positions。 Let him e！ I am not afraid of t