After the first fierce battle with the demons, the Great Wall guards suffered heavy losses, and there were almost no Yuan Qi cannons left on the front wall. The demons obviously came prepared this time, and the guards sent to the Western Regions were unable to break through the blockade of the demons every time, and finally had no choice but to retreat to the city.

In the next few days, the demons did not launch the same fierce attack as before, but camped far away. The Great Wall Guards were able to take a breather and recuperate.

"Sir, since we can't send troops to chase the demons in the Western Regions, we can only inform the army of the Western Expedition as soon as possible." Su Lie said.

"Hey, that's all there is to it, immediately arrange the best cavalry, send the news out, tell them what is happening here, and that there is a fast demon army advancing towards them. Also, immediately ask the soldiers to repair the smashed city wall, the vitality cannon is too late to repair it, and all the large bow and ballista carts are mobilized on the city wall in case of danger. Gao Chang said respectfully.

"Obey, and the last general will command someone to do it." Su Lie responded.

"Sir, we should also report the situation here to Chang'an in time." Standing aside, Baili Shoujo added.

"That's right, I was almost confused, this is the most important thing, let the imperial court allocate us military salaries again, so that we can repair the Yuan Qi Cannon in the future, no, we will build the Dongfeng Altar next time, it can't be like the current Yuan Qi Cannon, the range and power are not enough to deter the demons." Gao Chang said respectfully.

"Sir, how can the demons have flying trap wings, this is too incredible. Otherwise, our Yuan Qi Cannon would not have been destroyed so much. Baili Shoujo asked suspiciously.

"Yes, I've never seen them used before, and this time they've all learned to feint, and their strategic capabilities are not what they used to be, so we can't take them lightly in the future." Gao Chang said respectfully.

"I've been at Jixia Academy for two years, and I've never heard of a mechanical wing. So there can only be one possibility that can be explained, the Book of Heaven. In the war between humans and demons, the demons snatched part of the Book of Heaven, and the rest was left in Jixia Academy. The records of the organ wings must be left in the part of the heavenly book that was robbed. We'll collect the downed trap wings, and I'll ask my friend Lu Ban, who is still studying at Jixia Academy, to help us build our own flying trap wings. Baili Xuance said.

"Haha, great, in the future, with the flight wings, we won't have to be so passive. I will gather all the blacksmiths and carpenters in the city, and they will all be under the command of your friend. So, Xuan Ce, you should go to Jixia Academy now and bring back your friend to me. Gao Changgong was very pleased.

"Yes, the subordinates will leave immediately." Baili Xuance said.

The messenger cavalry that was sent out, riding fast horses, galloped quickly westward on the Great Wall, and changed to new sentry horses every hundred miles. After Su Lie arranged everything, he was always worried about whether the news would be delivered in time, otherwise, the army of the Western Expedition would suffer a huge blow. It is unknown whether the former captain of the women's team, as well as Kai, who was escorted home by his sister, will eventually return to the Great Wall safely and fight alongside him. This kind of hidden worry gradually locked up on Su Lie's brows, and it was difficult to stretch.