Dawn broke. The early morning of January 10, 1923, descended upon the Korean landscape, and the roar of artillery echoed through the mountains. The road leading to Pyongyang was relatively flat, and heavy Japanese artillery fire was pounding this sector ferociously. This area was defended by the Northeast Army's 23rd Army. The Army Group Command had long anticipated that this would be a likely point for a Japanese breakthrough attempt, so preparations were extensive.

Sure enough, once the artillery duel began, the Japanese 6th Division launched an offensive against the Northeast Army along the flatter terrain. The engagement escalated from contact to fierce combat in a very short time. Facing wave after wave of Japanese assaults, the 23rd Army, though under immense pressure, held its defensive line steady. When the 23rd Army's 105mm howitzers, positioned behind the lines, joined the fray, the already grievous Japanese casualties began to mount rapidly, and their ferocious offensive was forced to slow down.

At 9:00 AM, the 5th Army was standing ready in full battle array. Suddenly, an artillery bombardment targeting the 5th Army began. Deputy Regimental Commander Zhuang Pengyun soon received a phone call: the 2nd Battalion, which had taken over the defensive positions from the 3rd Battalion only yesterday, had suffered heavy casualties. The 2nd Battalion's deputy commander was killed in action, and both the battalion commander and the political commissar were seriously wounded. Zhuang Pengyun immediately led the 3rd Battalion, which had withdrawn yesterday for rest and replenishment, to move up and reinforce them.

On the way, Zhuang Pengyun felt puzzled. Were the Japanese intending to use this position as their breakthrough point? From an operational judgment, there was a passage behind this position leading directly to the rear, but it wasn't wide. Moreover, the Northeast Army had already established defensive lines along that passage. It wasn't the optimal location for a breakthrough.

When he arrived at the front lines, Zhuang Pengyun felt he understood. During his time at the military academy, in the artillery courses, instructors would recount various extreme case studies in special lectures. One of them was called "Heavy Artillery Shaving the Mountain."

It was termed an extreme case precisely because even the instructors didn't quite believe such a thing would actually happen, so it was always a very lighthearted class. Zhuang Pengyun felt like he had just encountered it.

This position originally had no particularly critical strategic points. Yesterday's shelling had already destroyed the three key points on the position that posed the greatest threat to the Japanese. The previous commander and deputy commander of the 2nd Battalion had been blown to pieces directly at those key points.

Now, this position was unremarkable, possessing no other characteristics besides a slight height advantage. After this round of shelling, the position was battered and broken, becoming a weak point convenient for a breakthrough.

Watching the Japanese troops beginning their assault, Zhuang Pengyun hurriedly directed the 2nd Battalion to join the defense. An ominous thought popped into his head: *Am I going to die here?*

Just as he was feeling uneasy, the soldiers were stunned to see four peculiar silhouettes emerge from amidst the Japanese infantry. They were machines resembling tortoises, with a track on each side of the lower half, similar to a tractor. On the upper middle section, there was a machine gun firing continuously.

When the Northeast Army's heavy machine guns fired at them, the Japanese infantry immediately scattered away from these iron tortoise-like machines. Some Japanese troops hid behind the machines, advancing alongside the "Iron Turtles" while firing.

Machine gun bullets struck the Iron Turtles and ricocheted off harmlessly. Although mortars fired shells, the Iron Turtles kept moving and were hard to hit. Moreover, they didn't move in a straight line but turned left and right, increasing the difficulty of landing a hit.

They crushed the road surface, crushed the barbed wire, and utilized their height advantage to sweep the Northeast Army trenches with fire. The firepower in the Northeast Army trenches directly facing these Iron Turtles was instantly annihilated.

This was a "tank." Recovering from his shock, Deputy Regimental Commander Zhuang Pengyun immediately realized what his unit was facing. The Northeast Army was also developing tanks and conducting tank training. The tanks used for training were made of wood and canvas mounted on cars. They could be dealt with using stones and pencils, and everyone jokingly called it "sticking a scallion in a pig's nose — putting on a show."

It was only when he encountered a real-world tank that Zhuang Pengyun witnessed with his own eyes that this thing was no joke. His training regulations immediately provided the countermeasure in his mind, and Zhuang Pengyun instantly ordered, "Rifle grenadiers! Prepare anti-bunker rounds! Prepare anti-bunker rounds!"

Receiving the order, the soldiers snapped out of their daze. After rummaging through the artillery ammunition, the anti-bunker rounds were found. To defeat the enemy's thick, fortified bunkers, the Northeast Army had developed anti-bunker rounds. These were metal jet rounds.

However, because this type of ammunition was still somewhat classified, and the Northeast Army didn't have many real bunkers to target, the artillerymen didn't stock many and rarely used them.

Seeing the infantrymen find and equip the anti-bunker rounds, Zhuang Pengyun breathed a sigh of relief. He immediately ordered the machine guns and mortars to focus their full power on the infantry following behind the Japanese tanks. They absolutely could not allow the Japanese infantry and tanks to coordinate.

Under the intense firepower, bullets flew and shells exploded around the Japanese tanks. One unlucky Japanese tank was hit on the upper side of its top by a 60mm mortar shell. With the explosion, the tank shuddered and stopped moving.

However, because the Northeast Army's firepower had shifted targets, their position immediately came under fierce attack from Japanese infantry support fire. The already heavily damaged position was beaten to the point where the defenders could only struggle to protect themselves.

The other three Japanese tanks accelerated their charge. Seeing them crush through the barbed wire, they rushed right up to the front of the Northeast Army trenches. Fortunately, the Northeast Army trenches were relatively wide, and these Iron Turtles couldn't cross them immediately. However, the Japanese tanks turned to find easier crossing points while their turrets rotated in the opposite direction, their machine guns continuing to sweep the Northeast Army trenches.

This was exactly the World War I tactical example studied at the academy: European nations attempting to use tanks to break through trenches and guide infantry to attack deep into the positions.

The infantrymen targeting the armored weapons had already inserted the anti-bunker rounds into their muzzles and moved close to these Iron Turtles. One infantryman raised his rifle and pulled the trigger. The rifle grenade flew out of the muzzle, traveling at a not-so-fast speed toward the Japanese tank. The rifle grenade, no more than 6 centimeters in diameter, hit the tank. The explosion was not violent.

But the tank shuddered once and surprisingly stopped moving and firing.

Seeing that it might be working, other infantrymen quickly followed up, attempting to aim at the third tank. At this moment, the turret of the first Japanese tank, which had been hit on top by the mortar, suddenly rotated. Its machine gun roared again, directly hitting two Northeast Army soldiers whose bodies were exposed. Amidst splashing blood, the two soldiers fell.

Zhuang Pengyun had just briefly reported the tactical situation to the regimental commander and requested reinforcements. As he put down the phone, he saw the two soldiers attacking the Japanese tank fall. Seeing the Japanese swarming toward this breakthrough point, Zhuang Pengyun ordered 2nd Battalion Commander Li Fuguei, who looked somewhat panicked, "Give me a squad of elite troops. You take charge of command. I'll lead that squad to take out the Japanese tanks."

Hearing this order, a trace of shame flashed across Li Fuguei's face, and he hurriedly said, "Deputy Commander, let me lead them."

Zhuang Pengyun was tempted, but in a split second, he felt that there was probably no one in the 2nd Battalion who could complete the task. He shouted, "Cut the crap! Hurry up and act on my orders!"

Soon, a squad of troops began to move, following Zhuang Pengyun. After yesterday's observations, Zhuang Pengyun had confidence in Li Fuguei's command ability. Facing real tanks for the first time, Zhuang Pengyun didn't even have much confidence in himself.

Just as he was leading the special combat unit through the trenches, carrying anti-bunker rifle grenades and approaching the Japanese tanks, he suddenly saw two more soldiers stand up one after another in the trench where the previous two soldiers had fallen. They aimed and fired at the two nearby Japanese tanks.

Two anti-bunker rifle grenades crossed the distance of a dozen meters at a speed visible to the naked eye, successively hitting the two tanks and terminating their movement.

The remaining tank, seeing the situation turn unfavorable, began to retreat. At this moment, the Japanese troops behind them seized the opportunity of this gap to charge up regardless of casualties, killing their way into the Northeast Army's 2nd Battalion trenches. Brutal hand-to-hand combat erupted immediately.