When Lü Pu reached his camp he called in his adviser Chʻên Kung. The latter proposed a new stratagem. He said, “In Puyang there is a rich family, Tʻien by name, who number thousands, enough to populate a whole district in themselves. Make one of these people go to Tsʻao Tsʻao’s camp with a pretended secret letter about Lü Pu’s ferocity, and the hatred of the people, and their desire to be rid of him. End by saying that only Kao Shun is left to guard the city and they would help any one who would come to save them. Thus our enemy will be inveigled into the city and we will destroy him either by lire or ambush. His skill may be equal to encompassing the universe but he will not escape.” Lü Pu thought this trick might be tried and they arranged for the Tʻien family letter to be sent. Coming soon after the defeat, when Tsʻao Tsʻao felt uncertain what step to take next, the secret letter was read with joy. It promised help and said the sign should be a white flag with the word “Rectitude” written thereon. “Heaven is going to give me Puyang,” said Tsʻao joyfully. So he rewarded the messenger very liberally and began to prepare for the expedition. Then came Liu Hua saying, “Lü Pu is no strategist but Chʻên Kung is full of guile; I fear treachery in this letter and you must be careful. If you will go, then enter with only one third your army leaving the others outside the city as a reserve.” Tsʻao agreed to take this precaution. He went to Puyang, which he found gay with fluttering flags. Looking carefully he saw among them, at the west gate, the white flag with the looked-for inscription. His heart rejoiced. That day, just about noon, the city gates opened and two bodies of soldiers appeared as if to fight. Tsʻao Tsʻao told off two of his captains to oppose them. Neither body, however, came on to engage but fell back into the city. By this move the assailants had been drawn close up to the drawbridge. From within the city several soldiers were seen taking any chance of confusion to escape and come outside. To Tsʻao Tsʻao they said they were clients of the Tʻien family and they gave him secret letters stating the signal would be given about watch setting by beating a gong. That would be the time to attack. The gates would be opened. So the rescuers were stationed and four trusty captains told off to accompany Tsʻao Tsʻao into the city. One of these, Li Tien, pressed upon his master the precaution of letting him go first. But Tsʻao Tsʻao bade him be silent. “If I do not go, who will advance?” And so at the time appointed he led the way. The moon had not yet arisen. As he drew near the west gate they heard a crackling sound, then a loud shouting, and then torches moved hither and thither. Next the gates were thrown wide open and Tsʻao Tsʻao, whipping up his steed, galloped in.