On the tenth day of the fifth lunar month of the seventh year of Zhou Xiande, Chai Rong issued an order to make Wu Yanzuo of the Xuanhui Southern Court the right to stay in Tokyo and sentence the affairs of Kaifeng Prefecture, and to make Zan Jurun the deputy envoy of the Xuanhui North Court, and to deploy Zhang Mei as the third envoy. On May 20, Chai Rong drove his own expedition, led more than 100,000 horses and infantry troops and the "Shenji Army" to leave Kaifeng and went to the Northern Han Dynasty. On the tenth day of the sixth month of the lunar calendar, Chai Rong drove to Luzhou.

Luzhou, as a necessary place for the Later Zhou to attack the Northern Han, has been the forefront of the confrontation between the Zhou and the Han for several years. Therefore, Chai Rong's expedition to the Northern Han Dynasty used this place as a bridgehead for attacking, and a large number of war materials and grain supplies were gathered here.

Thanks to the conscientiousness of the "Dark Feather" Kaifeng branch and the various halls of "Dark Feather" along the line from Kaifeng to Luzhou, so since Chai Rong led the army to leave Kaifeng City, until the Later Zhou army was stationed in Luzhou, to prepare for the upcoming war against the Han Dynasty, and the marching route of the various departments of the Later Zhou War; the supply and transportation of military equipment, grain and grass and baggage of the Later Zhou Army; Chai Rongzhongjun's walking and stationing arrangements, and other related news were detected by the "Dark Feather" secret agents one by one, and through the corresponding transmission channels, with the fastest transmission path, a steady stream of transmission to the "Dark Feather" headquarters in Beiping City. Subsequently, through Yang Xin, the chief military officer of Lingxian Mansion, Guo Wuwei, the liaison envoy sent by the Northern Han Dynasty, and Yang Ye, who had been transferred to Taiyuan City to preside over the defense, it was finally handed over to the Northern Han Emperor Liu Jun. Under normal circumstances, the time it takes for such a message to pass from the detection of intelligence to the time Liu Jun sees Yang Ye's submission, usually does not take more than three days.

After the Later Zhou army was stationed in Luzhou, because it was only more than 200 miles away from Qinzhou, a border town of the Northern Han Dynasty, the fine work and secret agents of the Northern Han Dynasty had the ability to observe and probe the Later Zhou army, and it took much less time to directly transmit the news back to Taiyuan than the "Dark Feather" forwarded from Beiping CityThe Taiyuan branch directly forwarded to Yang Yewai, and "Dark Feather" no longer provided other information to the Northern Han court about the Northern Expedition of the Later Zhou Dynasty.

While the "Dark Feather" (Intelligence Department) was fully committed to providing various information to the Northern Han Dynasty, the other functional departments of the crossing team were not idle, among which the Ministry of Agriculture, the Ministry of Science and Technology, the Ministry of Logistics and the Ministry of Commerce and Trade were fully engaged before the war began. One of these four departments is responsible for managing all the fields and properties within the jurisdiction of the crossing team and even the entire Beiping Army, one is responsible for the production of all equipment and weapons and equipment of the crossing team, one is responsible for managing the special and civilian materials of the crossing team, and the other is responsible for the marketing and trading of various tradable products of the crossing team. The reason for the busyness of these four functional departments is a grain and grass and ordnance trading agreement agreed upon by the two sides after the Northern Han Dynasty court and the crossing team formed a secret alliance against the Zhou Dynasty.

According to this agreement, under the condition that the roads are clear, the Beiping Army will continue to provide the Northern Han court with grain, grass, ordnance, and other war materials, and the Northern Han court will have to pay the corresponding expenses to the Beiping army according to the price agreed in advance -- after all, the Beiping Army has been established for a very limited time, and last year because the 16 states were only exempted from paying taxes for the whole year because of the war, so the Beiping Army Jiedu Mansion, which only relied on its own industry to provide economic income and had to support tens of thousands of elite troops, was not very rich. It was not yet able to provide free assistance to the Northern Han court. Of course, considering the alliance between the two sides and the need to fight together against the Later Zhou court, the Beiping army provided the Northern Han court with various materials at a very favorable price or even at a loss, so that the Northern Han court could obtain high-quality materials and equipment in quantities far below the market price, at least in the eyes of the Northern Han court. As for whether the Beiping Military Festival Mansion is losing money or making money, it can be seen from the elated appearance of the Ministry of Commerce and Trade when it fulfilled this agreement, and the joy on the face of Hong Yan, deputy director of the Finance Department. …,

Although it took a lot of time to transport grain, grass, and war materials from Beiping City to Taiyuan City due to the restrictions of transportation tools in this era, but thanks to the high load capacity of the four-wheeled carriage and the extremely large number of carriages owned by the crossing team, from the first convoy from Beiping City on the tenth day of the fifth month of the lunar calendar to the transportation channel between the two sides on the 25th day of June of the lunar calendar when the transportation channel between the two sides had to be closed because the Zhou army gradually approached Taiyuan City, the crossing team alone transported more than 100,000 stone of grain into Taiyuan City. Equipment and other materials are also piled up.

The reason why the Beiping Army was able to deliver so much grain to the Northern Han court in such a short period of time was that, on the one hand, there were thousands of four-wheeled carriages that could carry more than 3,000 catties of goods each, and on the other hand, because the crossing team had corn that should not have been introduced and planted in Eurasia so early in this era, an alien species whose yield was several times that of wheat in the north in this era. Although the people of this era were not completely accustomed to the new grain of corn, they always felt that this thing did not taste as good as rice and white flour. But people are still very adaptable, especially when they are hungry. Therefore, Zhao Min'an, who is in charge of the Ministry of Agriculture, is very confident that when the people of the Northern Han Dynasty cannot harvest the grain in time because of the war and begin to go hungry, they will never dislike the taste of rice and white flour.

If it is said that the original agreement with the Beiping Army was made out of consideration that the enemy's enemies were friends, and that such an alliance would not make the situation facing the Northern Han more difficult regardless of whether it succeeded or not, it was an attempt to try it out. Then, when the Beiping Army really followed the previous agreement, not only sent detailed information about the northward march of the Later Zhou army, but also provided a large amount of grain, grass and military materials for the Northern Han court, Liu Jun, who was originally restless because of the Northern Expedition of the Later Zhou Army, and a group of civil servants and generals of the Northern Han Dynasty gradually settled down, and the strength of their monarchs and ministers to fight to the death with the Later Zhou army gradually came up.

Just when the monarchs and ministers of the Northern Han Dynasty were united in their efforts and were ready to fight to the death with the Hou Zhou army with the all-round assistance of the Beiping Army, "Dark Feather", who had not directly provided intelligence information to the Northern Han court for many days, suddenly made a new move. A piece of top-secret information came out of the palace room of the "Dark Feather" Kaifeng Branch, through the "Dark Feather" Luzhou Branch in the Later Zhou Dynasty, the "Dark Feather" Qinzhou Branch and Longzhou Branch in the Northern Han Dynasty to the "Dark Feather" Taiyuan Branch, and then transferred from the newly added temporary special room of the "Dark Feather" Taiyuan Branch, which was specially responsible for transmitting news to Yang Ye, and sent it to Yang Ye, who was in charge of the urban defense affairs of Taiyuan City.

Although the content of the information was only a few lines, the monarchs and ministers of the Zhou State agreed that regardless of whether the attack on the Han State could be completed in one battle, it was necessary to move all the Han people in the places where the army passed to the territory of the Zhou State, so as to carry out the strategy of drawing salaries from the bottom of the kettle. But in the face of such a strategy that can be called a "desperate plan", Yang Ye did not dare to delay for a moment, and immediately entered the palace to ask to see Liu Jun, and handed this information to his adoptive father's imperial case.