Li Shimin was worried about the safety of Su Dingfang's Tang Dynasty, but Su Dingfang didn't think so, when he deliberately let go of the people sent by Pyongyang City to ask for help, he was already mentally prepared, because he learned from the news from Pyongyang City that Quangai Suwen didn't bring many supplies, in other words, there were so many troops stationed at Bogoukou, but the supplies were insufficient, and how many days could he stay if he died?

It is also in this situation, so Su Dingfang has long been ready to encircle the point and send reinforcements, as long as Quangai Suwen dares to bring troops to come, he can take advantage of the opportunity of the other party's labor expedition to defeat this support army in one fell swoop, although he only has 10,000 cavalry under his command, the other party is five times as much as him, but for the Tang army, it is not uncommon to win more with less.

However, Su Dingfang did not intend to wait like this, because in the news sent by Pyongyang City, in addition to telling him that Quangai Suwen did not have time to take away the materials in the city, there was also a more important news, that is, the messenger in the city told Su Dingfang that they had secretly persuaded the guards guarding the west gate of Pyongyang, as long as Su Dingfang agreed, they could open the city gate and let the Tang army enter the city.

"Keeping the promise, do you think this news is credible?" In the big tent, I saw Su Dingfang pondering for a while, and then he suddenly turned his head to look at Pei Xingjian, who was sitting on the side, and asked, for the information sent by the city, Su Dingfang also had a half-believing attitude, the information that Quangai Suwen did not take the materials should be credible, but the other party said that he would open the city gate to welcome them into the city, which made him have to be cautious.

"I can't say for sure, but I don't think it's like a decoy, otherwise I wouldn't have told us such an important news that Quangai Suwen didn't take too many supplies, after all, compared to this, they could have replaced it with another less important piece of information." Pei Xingjian also shook his head at this time and said, although he couldn't say for sure, he still tended to believe that the people inside should really want to open the city gate.

"I think so too, now it is the eldest son of Quangai Suwen who manages Pyongyang City, it is said that he is still very young, I think he should not have the courage to dare to use such important information as bait, unless he wants his father to die, and King Rongliu can leave a lot of loyal ministers at the beginning, although he was killed a lot by Quangai Suwen, but there are still some people lurking, and now that Quangai Suwen is not in Pyongyang, these people naturally jumped out." Su Dingfang also said slowly at this time.

"If it is really a letter from the ministers who are loyal to Rongliu, then we can try it, and as their letter says, if we agree, a red flag will be raised at the camp gate, and in the evening of three days, they will open the west gate." Pei Xingjian looked at the information sent from the city again at this time and said.

"Then give it a try, whether it is a bait or not, as long as they dare to open the city gate, Lao Tzu's army will dare to rush in, and then see how the little force in their city can resist!" Su Dingfang finally made a decision at this time, he was originally an adventurous general, although the news was a little suspicious, he still decided to take a risk.

Pei Xingjian also felt that it was feasible, although they had to take some risks, but if they succeeded, they could take Pyongyang City in one fell swoop, which was a great achievement, and as far as he knew, there were not many defenders in Pyongyang City, even if the other party really had any conspiracy, but in the face of absolute strength, they could only be crushed.

After making a decision, Su Dingfang also immediately convened the generals in the general to discuss the matter, after all, this news is now only known to their teachers and students, such a big decision naturally needs the support of other generals in the army, but this is not a big problem, after all, half of the 10,000 cavalry are Su Dingfang's old subordinates, and the rest of the people are also very convinced of him, so as long as he makes a decision, no one in the army will oppose it.

Sure enough, when the generals of Su Dingfang gathered up and told them that someone in the city was going to open the city gate, these generals were all excited, even if Su Dingfang repeatedly emphasized that there were risks, but they still couldn't stop these people from making meritorious contributions, especially Pyongyang City is the capital of Goguryeo, and the Tang Dynasty allowed the soldiers to collect the spoils of war, and then they were the first to enter the city, even if Su Dingfang Han army was strict, but just to occupy the Goguryeo palace and the mansions of some high-ranking officials, It's enough for them to scavenge a lot of good things.

The word fame and fortune is the most moving, and as long as the city of Pyongyang is captured, then Su Dingfang and his generals will have all the "fame" and "profit" they need, so in the end, they unanimously decided to take a risk, and Pei Xingjian immediately raised a red flag at the entrance of the camp in accordance with the agreement on the letter.

In the next time, Su Dingfang sent people to inquire about the news in the direction of Bogoukou on the one hand, to prevent Quangai Suwen from coming back and not getting the news, and on the other hand, he was also waiting patiently, and at the same time, the barracks were also loose on the outside and tight on the inside, everything was as usual on the surface, but the arrangements had been made secretly.

On the evening of the third day, when it was almost the second watch, the barracks was quiet as usual, even the bonfires were extinguished, and the whole barracks slowly fell into darkness.

However, the Goguryeo people at the head of the city did not find out, Su Dingfang took advantage of the cover of the night, personally led the selected 8,000 people out of the camp, in order to prevent any noise, the horses were tied to their hooves, and the horses' mouths were also covered with halters, and everyone did not ride horses, so they led the horses quietly to the west gate of Pyongyang City.

However, Su Dingfang was also very careful, in order to prevent the Goguryeo people from diverting the tiger from the mountain, so he deliberately left 2,000 cavalry, which was personally commanded by Pei Xingjian, so that if the Goguryeo people were killed in the camp, they would not lose their lair.

Of course, compared to Pei Xingjian and others who stayed in the camp, the real danger was Su Dingfang's 8,000 people, in case the news was really a bait, then the Goguryeo people in the city must have set a trap, so Su Dingfang took away most of the soldiers and horses, whether it was a trap or not, he had to break through, in case they gambled right, then today is the day when the horse stepped on the Goguryeo palace.

Time passed minute by minute, and finally came to the agreed third watch, according to the agreement on the letter, at this time the messenger should open the city gate, so Su Dingfang and the others also stared at the city gate with wide eyes, as soon as the city gate opened, they immediately rushed in!