The first tentative attack was frustrated, Qin Qiong had to withdraw the army back, Cheng Biting Jin Qi jumped straight to his feet, he had to get on the hot air balloon to personally check the terrain of Marudu City, no matter who persuaded him, it was useless, Qin Qiong was not good at pressing him as the main general, and finally had to agree, but Cheng Biting Jin really flew into the sky in a hot air balloon, of course, there is a rope tied under this kind of reconnaissance hot air balloon to prevent the balloon from being blown to other places.

Cheng Yanjin flew to the sky to observe the pill capital city, Qin Qiong was not idle here, and kept urging the mountain to transport the siege equipment up, but this mountain road was not wide, and it was difficult to transport it from the bottom to the top, plus those siege equipment was also very heavy, so the speed of transportation was not satisfactory.

Originally, Li Xiu thought that Cheng Biting Jin would come down soon after going up, after all, although it was clear from the sky, at most it was just to observe the general situation in the city, so as to make a reference when attacking the city in the future, but what he didn't expect was that Cheng Biting Jin stayed for nearly an hour after going up, and finally estimated that the fuel on it ran out, so the signal slowly fell, and the people below also pulled the rope to prevent the hot air balloon from falling to other places, in case it fell into Marudu City, it would be bad.

"Uncle Bao, I have thought of a way!" As soon as the hot air balloon landed, Cheng Yanjin jumped out of the hanging basket excitedly, and then grabbed Qin Qiong's arm and shouted.

"What's the solution?" Qin Qiong was stunned at first when she saw Cheng Yanjin's excited appearance, and then couldn't help asking.

"It's not clear for a while, let's find a place to talk in detail!" Cheng Yanjin was still very excited at this time, and then pulled Qin Qiong down the mountain, the place on the mountain was too small to even open the tent, so the army was divided into several parts to take turns, and when resting, he still had to go to the domestic city under the mountain.

Cheng Biting Jin took Qin Qiong and Li Xiu down the mountain together, and then came to his room excitedly, and was not in a hurry to say what he thought, but took the pen and paper and began to draw, although Cheng Bitingjin's painting skills were miserable, but soon Li Xiu and Qin Qiong saw that Cheng Biting Jin was drawing the general structure of the pill capital.

After waiting for a while, I saw Cheng Yanjin throw down the brush and said with a smile: "Come and see, this is the general topography of Marudu City, although I didn't draw it well, but I have drawn some important places!" ”

Li Xiu and Qin Qiong also came together to watch at this time, only to see that the shape of Marudu City was round in front and pointed in the back, but there were many strange protrusions in the middle, which looked like an egg with thorns, and I didn't know if the shape of Marudu City was originally like this, or if it was the deformation of Cheng Biting Jin's painting, but these didn't matter, the key was some important information marked on Marudu City.

The domestic city leads to the mountain and is directly opposite the south gate of Marudu City, and it is also the main gate, and the defense of this gate is also the tightest, and in addition to this gate, there are two other city gates in Marudu City, which are in the northeast and southwest, but the city gate in the northeast is very small, and it is also a water gate, because there are two water sources in Marudu City, and finally converge into a river, this river flows from this city gate in the northeast, and there is an iron gate on the water gate, and it is impossible to enter and exit at all.

In contrast, the southwestern gate looks much more normal, and as long as you bypass it from the south, you can see that there is a large flat open space in front of the southwest gate, which looks very suitable for attacking.

However, if the Tang army really attacked from the city gate in the southwest, it would just fall into the trap of the Goguryeo people, because the southwest city gate looked easy to fight, but behind the city gate was a large urn city.

The so-called urn city, just like its name, is like a water urn in general, surrounded by city walls, as long as the enemy rushes in from the city gate, and then close the city gate, the top of the head is like arrows raining down, the enemy will be like a mouse into the water urn, in the end can only be ten dead and lifeless, it can be said that it is very vicious, of course, when the Goguryeo people built this urn city, I am afraid that they would never dream that one day the enemy could fly to the sky to observe the situation in the city.

"Then according to what you observed, we can only attack from the main gate, after all, compared to the other two city gates, although the main gate is dangerous here, it is at least easier to fight than that urn city." After listening to Cheng Yanjin's narration of Pill Capital City, Qin Qiong couldn't help but show a contemplative expression.

To the northeast is the Water Gate, and there is also an iron gate, and at the same time there will definitely be heavy troops, it is difficult for the Tang army to approach, and the southwest of the urn city is also a headache, and the difficulty of attacking is even higher than the main gate they are trying today.

"Yes, although this main gate seems to be dangerous, but in fact, there is no way to crack it, through the temptation just now, we can see that the main gate is difficult to beat, in addition to the terrain, the most important thing is that there are two peaks on both sides in front of the city gate, there are fortresses on the peaks, and there are hidden soldiers inside, so that the fortresses on the two peaks and the defenders on the city gate form a horn momentum, and attacking one will inevitably encounter the other two." Cheng Yanjin explained the situation at the main gate in detail at this time.

"I know all of this, but what's the use of saying this, do you have a way to conquer those two fortresses?" Qin Qiong asked with a frown at this time, he also knew that the two fortresses outside the main gate were the key, but he couldn't think of any good way to overcome them for a while.

"Hehe, I really thought of one, when I was observing on the hot air balloon just now, I found that the two peaks outside the main gate were too steep, there was no way to climb them around, and the city wall could not be built to the peak, so the Goguryeo people built a suspension bridge between the city wall and the mountain peak, and the materials and troops needed in ordinary times also need to be transported by the suspension bridge, as long as we destroy these two suspension bridges, the Goguryeo people will definitely not be able to repair them in a short time, and then it will be our chance!" Cheng Yanjin finally told his method at this time.

"Suspension Bridge?" Li Xiu couldn't help but show a surprised expression when he heard Cheng Yanjin's words, he really hadn't found it before, but looking at the map drawn by Cheng Yanjin, it was hanging on the back of the mountain peak, and he couldn't see it at all when he stood in front of the city gate, so he naturally didn't find this problem, of course, it was still that sentence, I'm afraid that the Goguryeo people who originally designed the pill capital city would not have thought that someone would fly to the sky to observe the situation in the city.

"But this suspended bridge is on the back of the mountain, and it's so high, we can't reach it if we want to, unless you can fly ......" Qin Qiong didn't react at first, and said to himself with a frown, but halfway through speaking, he immediately reacted, and now Tang Jun can really fly into the sky, but he, a veteran, sometimes ignores this advantage.

"Hehe, although our hot air balloon is mainly used to observe and know, but at some critical moments, it can also be used to attack, such as the battle of Weishui, the hot air balloon has made a great contribution, it is said that a thrown grenade almost blew up Jieli." Cheng Biting Jin also bared his teeth at this time and said with a smile, if it was possible, he really wanted to try the feeling of throwing a grenade down from a hot air balloon.

"Since it is a suspended bridge, it should be covered with wooden planks on iron chains, and in this case, if you want to destroy such a bridge, it is better to use gunpowder, but to use fire oil!" Li Xiu also opened his mouth at this time to propose, sometimes there are more solutions than problems, no matter what kind of problem, there is always a solution in the end.

"Okay, let's try it tomorrow, I'll have someone prepare the oil!" Qin Qiong also said almost without hesitation, as long as the connection between the two peaks and the city wall is destroyed, with the scale of those two fortresses, I am afraid that there will not be much material stored, and as long as the Tang army increases its strength, it should be able to attack under the city gate, and then use gunpowder to blow up the city gate, and then it will be the death date of Quangai Suwen's father and son.

Li Xiu was also very excited at this time, and now he also began to study the detailed steps of destroying the suspension bridge with a hot air balloon, the first problem to be solved is the fixed people after the hot air balloon lifts off, if there is no human control, the hot air balloon will only float with the wind, so the best way is to use a rope to pull it as when observing and knowing it today, so that the hot air balloon can be controlled to reach the sky above the suspension bridge, and it is also convenient for continuous attack.

However, the load of a hot air balloon is limited, but if multiple hot air balloons are lifted into the air, it is easy to collide in the air, which is too dangerous, and after the hot air balloon is used up, it must be replenished, and this time must be as short as possible, otherwise it will give the Goguryeo people time to extinguish the fire and even re-pave the bridge.

The above small details seem to be small, but in fact, they are related to the success or failure of destroying the suspension bridge tomorrow, and it is also related to being able to break through the pill capital, so Li Xiu also calmed down and made a detailed plan, and finally discussed it with Qin Qiong and Cheng Yanjin, and then summoned the craftsmen to make some modifications for the hot air balloon to adapt to tomorrow's attack.

That night, Li Xiu almost didn't have all his eyes all night, and the craftsmen in the army were also busy all night under his command, and when it was early the next morning, they were finally ready, but what Li Xiu didn't expect was that the wind suddenly blew today, and the wind was not small, in this kind of weather, the hot air balloon was not only dangerous, but also difficult to control the direction, and finally could only discuss with Qin Qiong and postpone the plan.

It's just that even Li Xiu didn't expect that this wind would blow for several days, and it was a north wind, even if their hot air balloon rose into the air, it couldn't float to the side of Marudu City, which made everyone very helpless, and with the north wind, the weather became colder and colder, especially the temperature in the mountains changed greatly, and it may still sweat during the day, but it was a biting cold wind at night, and even snow would fall on some mountains.

The drop in temperature also cast a shadow on everyone's hearts, and if they didn't take Maruto Castle before the snow fell, it would be very difficult for them to retreat, let alone fight.