A month after that military meeting, the operation, named "Skyfire", entered its final phase. The name of this project is "Heavenly Fire", which means to take the Heavenly Fire and set the prairie on fire. Over the course of a month, the 2nd Division did a great deal of work.

First of all, it was to reconnoiter the situation of the two sections of the Great Wall, and Guan Xing sent several reconnaissance teams to walk along the Great Wall from both sides, and soon found out the damage to the two sections of the Great Wall. The gap on this side of the Inner Great Wall is not a big problem, and during this time, manpower was organized to repair it, and most of the places have been repaired.

There are also some gaps in the mountains, and there is no need to repair them, because it is estimated that the enemy will not choose such a place to pass, because it is much more difficult to climb these mountains than to climb a complete section of the Great Wall, and these places are inaccessible, and few people know that there are gaps in this section of the Great Wall. The gap in the Outer Great Wall was too late to be repaired, so people could only be sent to garrison it.

The gaps that are too late to be repaired should also be sorted out a little, mainly by taking local materials, moving some stones or shoveling some soil, and making some temporary stairs or slopes at the fracture of the Great Wall, so that people can get down immediately, this simple project can be completed quickly, and it does not take much time.

At present, the shuttle-shaped area between the inner and outer Great Wall is not very peaceful, and the Second Division does not dare to rashly send troops into it without dispatching a large convoy. How the garrison troops got to the passes and openings of the Outer Great Wall was a problem. Not only the garrison troops, but also logistical supplies are also a problem, and the garrison troops must not fail to eat or drink.

After thinking about it, Guan Xing finally decided to walk along the Great Wall. Most of the inner and outer sections of the Great Wall are intact, and people can walk on them, and the two ends are connected, and the two sections of the Great Wall are connected like an elliptical ring, starting from one place, walking around can also walk back to the original place.

As for the damaged place, then you have to go down and walk a mountain road, but these gaps are usually not big, the mountain road to go is very short, often more than ten meters to dozens of meters, the impact is not great, and people have been sent to build a staircase or an inclined city wall up and down, everything is not a problem.

Walking along the Great Wall, although it is a big circle, the distance is almost three times that of a straight line, but the safety is greatly enhanced. Moreover, not only can the troops go this way, but the logistical supplies can also be continuously transported to the garrison troops through this route.

Although the Great Wall is wide, it is built on a high mountain, and there are constantly steps up and down, and there are gaps from time to time, so it is impossible to use vehicles on this route, but it is no problem for people and horses to walk.

The 2nd Division, like the 1st Division, collected a lot of donkeys, mules and other livestock in the early stage, and these livestock could also walk on stairs and mountain roads, although the speed would be slowed down, but it was better than carrying them on their shoulders by manpower.

The men of the baggage team fastened the supplies on the backs of donkeys, mules and other animals, let them carry them, and walked all the way along the Great Wall, and at each garrison point, they unloaded a part of the supplies, and the unloaded animals turned around and returned the same way.

In this way, the work of the baggage team members is quite easy, they only need to pull the reins to walk, only occasionally when they encounter a gap, it is more troublesome to climb over the mountain road, most of the time it is quite comfortable.

The first difficulty was quietly solved, and the Great Wall has recently been crowded with people, but it has not attracted the attention of the Xianbei people. Most of the Great Wall is built on mountain ridges, relying on steep mountains to enhance the protective function, and the Xianbei people naturally avoid such mountains and try to carry out grazing on the plains, so the Xianbei people are unaware of the recent changes on the Great Wall.

The second thing the 2nd Division did was to send a large number of reconnaissance teams into the grassland and take a dragnet reconnaissance of this fusel-shaped area. Of course, it is impossible for the Han army to enter blatantly in military uniforms, and that is no different from looking for death.

Fortunately, commerce had a certain scale in this era, and many merchants went in and out of the grassland for a long time to do business with those steppe tribes. To put it nicely, these people are businessmen engaged in import and export business, and they are envoys to promote the circulation of goods and the integration of civilizations between the Han and Hu ethnic groups.

Regardless of the era, the Han court generally strictly forbade the sale of strategic materials to the grassland peoples. The most important strategic material is undoubtedly ironware, which is also the reason why many Hu tribes even lack iron pots and kitchen knives.

Iron tools were forbidden to be exported to the steppe in any dynasty, and other materials may be included in the embargo in different dynasties or at different times of the same dynasty, such as grain, salt, tea, cloth, etc.

The main reason why the imperial court forbade trading with the Hu people was that after the Hu people got these materials, they became stronger, and they would attack the Han dynasty in turn. In particular, iron tools can be used as weapons, and the Hu people used the iron tools they bought from the Han people to make weapons, and then used these weapons to invade the territory of the Han people to burn, kill and loot, what a disgusting thing.

The Han merchants who smuggled these iron tools to the grassland were not traitors and traitors? Businessmen seek profit, and many businessmen do not care much about how much harm they have done to the country and the nation for the sake of their own selfish interests. What's more, in this era, many people, especially businessmen, do not have the concept of a country, a nation, and of course no concept of patriotism.

These businessmen are the usual targets of dictatorship, but now is the time to use them. Guan Xing asked people to find all the merchants engaged in border trade, and under some coercion and temptation, all of them became their reconnaissance teams.

He sent all the caravans into the steppe at once to trade with the tribes, and at the same time placed scouts in these caravans to find out the location of the tribes.

For a time, the steppe was full of Han caravans. The Hu people often do business with them, and they are still very familiar with these caravans, although there are more caravans during this time, but they are about to spend the winter, and in previous years, before the winter, it is also the most frequent time for the caravanserais, because at this time, the merchants will come to buy the cattle and sheep that have been raised for a year, and sell the necessities used by the Hu people for the winter, such as grain, salt, etc., so the Xianbei people do not doubt him.

The solution to these two difficulties is simple to say, but it is actually not easy to do at all, and it is a lot of work. Especially the second difficulty, the second division took a full month, and it didn't dare to say that all the Xianbei tribes were found out, but the location of most of the tribes was just clear.

It is inevitable that some small tribes will slip through the net. After all, the grassland is too big, there are too many tribes, and there are some small tribes with very small populations that are too scattered, and the Second Division will not be able to find out all of them in the short term, so it has to let them go for the time being.

However, the population of these tribes is too small, and even if they are spared, they will not be able to make the climate. It's just that no matter how difficult these two difficulties are, compared to the third difficulty, they are trivial. The solution of the third difficulty is not something that can be accomplished by sending a few people from the Second Division, but also involves diplomacy and people's livelihood resettlement, which is actually beyond the scope of the Second Division's capabilities.