When Yue Fei first arrived in Youzhou, the Mongol army had already attacked, and more than half of the sixteen prefectures of Yanyun were easily attacked by the Mongol army, and the entire territory of many prefectures and counties was slaughtered, and the people fled in large numbers. Yue Fei led the army to take the initiative to attack the Mongol army, but lost due to too few troops, but successfully hindered the movement of the Mongol army, inflicted great casualties on the Mongol army, protected a large number of civilians to return south, and escaped the butcher's knife of the Mongol army. Then Di Feng and Han Shizhong also felt Youzhou, the three generals set a plan to fight together, with a small number of troops to the Mongolian army to launch a counterattack, one after another to the Mongolian army to give a fierce blow, at that time there was chaos in Mongolia, the Mongolian army had another epidemic, so they retreated, but Yanyun Sixteen Prefectures one-third of the land fell into the hands of the Mongolian army.

After learning that the Mongol army had entered the land of Yanyun, Zhao Gou repeatedly ordered the three generals to march to regain the lost territory, but at this time, the main force of the Song army had been wiped out in the battle of Liao, and the army led by the three generals was mostly newly recruited, lacking weapons and training, and the number was small.

Another "disobedience" of the three generals made Zhao Gou angry, but because of the unstable situation in the border area, he needed the three generals to guard the border, so he forbearance and did not send a decree to praise the three generals, but there was no response to the three generals' requests for food and salary support.

As a last resort, Yue Fei and Di Feng and Han Shizhong discussed, and began to use Zong Ze's method of guarding Youzhou that year, and set up a village in Tuntian, in order to hold on, but the Mongols did not give them enough time, and soon after the civil strife subsided, the Mongol army went south, probably the last time from the outbreak of the epidemic in the army was enlightened, the Mongol army used a stone thrower to throw a large number of corpses of soldiers and civilians who died due to the epidemic into the city during the siege of Youzhou, and as a result, the soldiers and civilians in the city were infected with the plague known as the "Black Death", and Yue Fei was only spared.

In order to heal the soldiers and civilians of the city, Yue Fei didn't know who he had to believe, and used his own blood as a material to make medicine, but although he healed some people, his own body was greatly damaged, and finally Youzhou City was breached, Yue Fei led the army to fight with the Mongolian army in a street battle, and died of exhaustion.

The Mongols had great respect for Yue Fei, buried his body in a coffin, and sent the Song army to send it to Danzhou, where Di Feng guarded, and Di Feng buried Yue Fei ceremoniously, built a temple to worship, and reported Yue Fei's death to the imperial court.

Knowing that Yue Fei died in battle, everyone in the Song Dynasty was terrified, and Zhao Gou was even more frightened, and soon it was rumored that the Mongol army bypassed Di Feng and Han Shizhong's defense area and was heading towards the interior of the Central Plains, and the exiled people also passed the "Black Death". Soon the "Black Death" really spread in the Central Plains and the city of Tokyo, causing a large number of deaths of soldiers and civilians in the Song Dynasty.

At this time, the Mongolian army was also tormented by the "Black Death", and began to return north, Di Feng and Han Shizhong guarded the local soldiers and civilians were also infected in large numbers, I don't know why, Di Feng and Han Shizhong also did the same thing as Yue Fei, with their own blood medicine to treat the army and civilians, and then with the blood of the cured people to continue to medicine, to heal others, but this method still can not stop the spread of the epidemic, Di Feng soon died of grief, Han Shizhong alone could not support, obeyed the advice of his subordinates, only led more than 1,000 uninfected soldiers to break through and return to the south, Han Shizhong was seriously injured in the battle, only four fingers left in both hands, after returning to Tokyo Kaifeng, he was impeached by the official and left his post without permission, his soldiers were not satisfied, killed the official and threw him into the river, Zhao Gou heard the news and dismissed Han Shizhong and sent him back to his hometown, and soon Han Shizhong died of depression.

The plague spread to the interior of the Central Plains, sweeping across the entire area north of the Yangtze River. Everywhere the plague went, there were dead people. According to the records of the literati of the time, "If a man were to die of the plague, all those who had visited him, had done business with him, and had carried him to the grave would soon follow in his footsteps." "In Kaifeng, Tokyo, the plague spread so fast that carts full of corpses poured out of the city like a flood, day and night. According to another scribe, in the city of Taiyuan, the scene was equally terrifying: "Because this disease is transmitted through the respiratory tract, when people talk, it is transmitted from one person to another." All the sick felt unbearable pain, and some were trembling all over; As a result, pustules appear on the arms and thighs, as large as bean pits, which infect and penetrate into the body, causing the patient to vomit blood violently. The horrific symptoms were ineffective and lasted for three days before death. It's not just that talking to a sick person can lead to death, it's that anything you buy, touch, or get from a sick person can die from infection."

In the face of a sudden plague, people cannot explain it, let alone treat it. In order to seek sustenance, people come to the monastery one after another, hoping to be protected and comforted by the gods and goddesses. Led by monks and Taoists, they prayed together and prayed to the gods and Buddhas to stop the spread of this plague. But their prayers came to nothing. On the contrary, there are more and more dead, and people are burying the dead who are sent in day and night. In order to stop the spread of the plague, the houses of the dead were sealed so that no one dared to step into them.

Under the attack of the Black Death, the entire Song Dynasty fell into panic. It has been found that anyone who is infected has little chance of recovery, and that it spreads so rapidly that it seems that one person can spread the whole world. In a state of panic, they even boarded up the doors and windows of the sick who were still alive, and eventually starved them to death inside. According to various documents of the time, because of the fear in the hearts of the people, siblings, uncles and nephews, husbands and wives abandoned each other, and even worse, parents abandoned their children without care. People are abandoning the sick and losing their possessions in order to save themselves. Others do the opposite. They believed that having fun in time would help protect against the Black Death. So they drank and sang and had merry, day and night. Sometimes they also break into other people's houses in search of a thrill to the senses. Because many people at the time abandoned their homes and property, they were condoned to do so. As a result, many premises have become public property, and these people use other people's belongings as if they were their own. Officials have all but disappeared because, like everyone else, they either die or get sick, or simply shut themselves and their families off and neglect their duties. Most commonly, however, large numbers of people leave their cities, homes, homes, relatives, and possessions and flee to the countryside. As a result, this behavior further contributed to the spread of the plague.