Since both parties had reached an agreement, Xiang Yu was no longer worried. The next day, he led an army of 400,000 to Hangu Pass.

However, this time the Hangu Pass was completely different from the previous time when the gates were wide open. The entire gate of the pass was tightly closed. Not only that, the people on the city wall did not see the familiar archers and crossbows. Instead, there were strange thick black tubes extending from between the battlements, pointing straight to the ground, and behind these thick tubes there were things like large shields, which looked extremely strange.

In addition, there are flags fluttering in the wind on the top of the city.

"It's a wordless flag, right? It seems the other party really wants to hold on here."

Seeing this, Fan Zeng also reached out and touched his beard, and then whispered. Hearing Fan Zeng's words, Xiang Yu frowned slightly and remained silent.

The so-called wordless flag refers to the flag of Fang Zheng's uprising army. In this era, most flags of various countries were their surnames or country names, such as Zhao, Qian, Sun, Li, etc. However, the flag of Fang Zheng's uprising army was unique. It was a red flag with no words on it. There was only a huge five-pointed star and a crossed sickle and hammer in the center of the flag.

Because of this, the princes called Fang Zheng's flag the "flag without words", and Fang Zheng's army the "army without words". On the one hand, this is true, and on the other hand, it is also a way of secretly belittling the other side. After all, only those of low status don't know how to write, which also implies that Fang Zheng's side is full of uneducated inferiors.

At this moment, the entire Hangu Pass was dead silent. No one could be seen and no sound was heard. However, everyone could see many human figures through the gaps in the huge iron shields, which showed that there were indeed people behind them.

“Attack the city!!”

Xiang Yu looked at the silent Hangu Pass and felt a little uneasy. Although Fang Zheng said that he could not use the magical power of piano music, the other party used 40,000 people against 400,000 people and acted so confident. Xiang Yu would not think that Fang Zheng was just pretending.

“Boom boom boom boom!!!”

Soon, the drums sounded, and the soldiers immediately pushed the siege equipment forward. Originally, the other side should have fired arrows to stop them, but the people on the other side of Hangu Pass just watched silently, without any reaction, as if there was no one inside.

Something was not right, but why exactly was it not right?

Xiang Yu was a general who had experienced many battles and had his own understanding and judgment of the situation. At this moment, he watched the soldiers advance so smoothly, but he couldn't stop feeling uneasy. Could it be that there were ambushes around? Or was there some kind of trap?

But as for ambushes, there is nowhere to hide them given the terrain of Hangu Pass. As for traps, the plain is flat now, and it is impossible to send cavalry first when attacking the city. So what's the use of traps such as tripwires and ditches?

However, just as Xiang Yu was thinking hard, a strange vision suddenly appeared.

"boom!!"

The soldiers pushing the siege equipment had just walked less than half the distance to the battlefield when they suddenly heard a loud noise like thunder. The next moment, everyone saw a flash of fire between the soldiers pushing the battering rams forward, and then the earth exploded instantly, directly blowing the extremely hard siege equipment and the soldiers into pieces.

The bloody remains of the soldiers flew in the air and fell to the ground with a "patter" sound, which made the soldiers behind them feel chilled. Before they could come to their senses, they heard several thunderous noises, and then the siege troops in front were swept by the flames that appeared on the ground again, and a large number of them were killed and injured in less than a moment.

"What on earth is going on?"

"Could it be lightning and thunder?"

Seeing this incredible scene, everyone was talking about it, and Xiang Yu subconsciously looked up at the sky, but the sky was blue, without even a shadow of a dark cloud. The sun was so bright, it was a sunny day, but even so, where did the thunder come from?

Thinking of this, Xiang Yu couldn't help but recall what Fang Zheng said before he left yesterday. He was also uneasy, but he still hardened his heart and gave the order.

"Keep attacking!!"

“Boom boom boom!!”

The sound of war drums continued, and soon the first batch of siege troops were completely defeated. But then the second batch immediately pushed the siege equipment and continued to advance. However, their fate was not much better. The second batch of siege troops had only walked about 300 meters further than the first batch when they completely collapsed. The third batch refused to go up no matter what, even if the military supervisor behind them whipped them in anger.

It's not their fault, the scene before them was just too weird. Not only were some of the people killed in the explosion, but many also had their arms and legs broken and were screaming in agony. Many were even swept up by the blast and fell backwards into the formation. Just looking at these miserable corpses, their morale dropped to the bottom.

“There must be something wrong with the ground.”

At this moment Xiang Yu also figured out what was going on. Although he didn't know what Fang Zheng had done, he was sure that the other party must have done something on the ground, so the place exploded when those people passed by.

"Break the city directly!"

The city-breaking equipment of this era was already very complete. In addition to the battering rams used to break through city gates and cloud vehicles for climbing city walls that are often seen in movies and games, there were naturally stone throwers, and a special device called a spear, which looked like an enlarged crossbow. The arrow alone was three meters long, and dozens of soldiers were needed to push the winch to fully load the bowstring.

Once this giant arrow is shot, almost nothing can stop it. This time Xiang Yu also knew that he was going to attack Hangu Pass, so he naturally would not forget these long-range siege weapons.

Xiang Yu did not use these to launch a major attack before, mainly because he was afraid that if Hangu Pass was damaged, it would be difficult to repair. If he could just rush in and take it, it would be the best. However, it now seems that it is not feasible to directly occupy Hangu Pass, so Xiang Yu has to take the second option.

Soon, with Xiang Yu's order, the soldiers behind him immediately got busy. However, at this moment, Xiang Yu suddenly saw a flash of light on the wall of Hangu Pass in the distance, and then...

"boom!!"

In just a moment, the siege equipment in the rear was instantly engulfed in flames, and several stone throwers were directly blown into a pile of wreckage.

"What's going on? What happened?"

At this moment, not only Xiang Yu was stunned, but the other soldiers were also in an uproar. However, before they could figure out what was going on, accompanied by a whistling sound, a series of flames suddenly broke out, completely enveloping the soldiers who were in formation.

In the blink of an eye, the 400,000-man army soon became a mess. No one had thought that they would encounter such an attack, and the roar and fire that accompanied the impact aroused the most primitive fear of mankind. Even the well-trained elite soldiers were panicked in this situation, not to mention the soldiers of the princes' army.

"Withdraw troops immediately, withdraw troops!"

Xiang Yu was a general, so he was not stupid. He knew that the situation was unclear and that he would collapse if he continued. So he pulled his horse and gave orders. Soon, the horn of retreat sounded, and then the 400,000 troops immediately retreated and left Hangu Pass far away.

Thus, the first day of the siege ended hastily.

“Hehehe.”

Looking at the retreating army, Fang Zheng, who was standing on the city wall, laughed. For a time traveler, making firearms is a must, not to mention Fang Zheng. After all, with the current production technology and science, black powder is not something that is difficult to control, but the device can only be made with what is available.

For example, the mines Fang Zheng had set up outside Hangu Pass were actually based on the products of the Ming Dynasty, with stone shells, gunpowder, and a mechanism as a striking device. The same was true for these artillery pieces. Even with current technology, they could not forge artillery pieces with a long enough range in the future, but they far exceeded the launch distance of the catapults of this era, and were sufficient to deal with most armies of this era.

After all, times have changed, my lord.

However, for Fang Zheng, what he brought to Xiang Yu was more than just artillery and mines.

"What on earth is going on with that Fang Zheng?!"

Xiang Zhuang returned to the tent angrily and complained to Xiang Yu.

"Didn't he agree with his brother that he would never use any magic or sorcery? This is simply a lie!"

"No, he is not lying. This is indeed not some magical power or sorcery."

But after hearing Xiang Zhuang's complaint, Xiang Yu shook his head and put down the iron piece in his hand.

"Do you know what this is?"

"What is this? A piece of iron? A shield?"

Xiang Zhuang took the iron sheet from Xiang Yu with suspicion and examined it carefully. It was an arc-shaped iron sheet that looked like the corner of a shield, but Xiang Zhuang felt that it was not the same as a shield.

"I don't know what this is, but I saw it clearly before. The strange cylinder on the city wall flashed with fire, and then a black iron ball flew out of it, and then fell directly to the ground and exploded... Well, it's really weird."

Xiang Yu had also received the true teachings of Xiang Shaolong, and had also practiced those internal skills. Therefore, Xiang Yu not only had a keen sense, but was also far superior to ordinary people in this respect. When he was first attacked, Xiang Yu used his internal skills to see and easily saw the strange scene on the wall of Hangu Pass in the distance.

"Isn't that still witchcraft?"

"Master Fang never breaks his word. I think this is definitely not witchcraft, but something we don't know yet."

Thinking of this, Xiang Yu couldn't help but recall the story Fang Zheng told him yesterday about his ancestors who ate raw meat and drank blood, wore animal skins and used stone axes... I'm afraid this is what he meant.

Now we just don’t know what methods Mr. Fang used.

"snort!"

Seeing Xiang Yu staring at the piece of iron intently, Xiang Zhuang stomped her feet and ran out in anger. She was very unhappy with today's failure, especially when she heard the rumors from the surrounding soldiers, which made Xiang Zhuang even more angry.

That’s right!

Thinking of this, Xiang Zhuang's eyes lit up.

Why not sneak into Hangu Pass and kill that guy? I can't beat him in a normal fight, but I don't believe I can't kill him by sneaking up on him? !