A divine healer, a general, a young marquis! Who can rival them!

That poisoned, Da Cheng-style arrowhead pierced Yang Hu and Qin Ying's hearts like a cold needle.

It lay quietly under the oil lamp, gleaming with a faint, cold light, as if silently telling a crime deeper and darker than colluding with the enemy for profit. On one side was the neat and orderly form of Da Cheng's military equipment, and on the other side was the black residue of the barbarian poison from beyond the Great Wall. These two things, which should have been irreconcilable, were strangely fused together on this small arrowhead.

The commotion in the wounded soldiers' camp gradually subsided as night deepened. Of the dozen or so soldiers who had been hit by poisoned arrows, only two were beyond saving due to their severe wounds; the rest were temporarily out of danger.

Back in that cramped medical tent, Yang Hu and Qin Ying finally had a moment of peace.

"Leaving weapons to the barbarians is already a capital offense of treason." Yang Hu placed the arrowhead under the oil lamp and said, word by word, "But now, not only has this weapon been leaked, but it has also been poisoned and turned around to kill my own Da Cheng's garrison."

Qin Ying disguised himself as a medicine boy, his face smeared with ash, but his cold eyes were now churning with overwhelming hatred.

Born into a military family and raised in the army, she knew better than anyone the profound sin that this poisoned, family-made arrowhead represented.

"This is no longer as simple as embezzling military supplies and extorting money." Her voice trembled violently, each word seemingly squeezed out from between her teeth. "This is about sending the garrison at this pass to their deaths in droves."

She knew all too well what this meant. The more people died on the city walls, the weaker the defenses became; the weaker the defenses, the easier it would be for the barbarians to breach the pass. A poisoned arrow killed not just one soldier, but severed the lifeblood of the entire pass.

"What a cruel heart." She closed her eyes. "For that shady business, they even treated their own guards as dead men paving the way."

"Not bad." Yang Hu nodded slowly, his eyes as cold as iron. "Leaking military supplies is for money. But poisoning weapons and specifically targeting their own troops... this is to ensure the complete fall of this border."

A parasite who leaks military supplies for personal gain, and a traitor who plots to lose the border and open the door to barbarians—these are two completely different kinds of evil.

The latter is a hundred times more ruthless and a hundred times more dangerous.

"That hand wants more than just money." Yang Hu's fingertips pressed heavily on the arrowhead. "What it wants is this barrier, the gateway to this country."

The light from the oil lamp flickered on his young face.

He laid the paper filled with names and details under the lamp again, pushing the layers deeper.

From the inferior weapons that led to the deaths on the city walls, to Section Chief Zhao of the quartermaster's office, to the clerk in the central command tent who hired someone to commit murder, and then to this poisoned arrow specifically designed to kill the defenders… all the clues, originally scattered in different places, are now tightly strung together by this small arrow. They all point to the same source: the hand hidden deep within the central command, a hand that has never even shown its shadow.

"This poison is refined to perfection," Yang Hu pondered. "Ordinary barbarians don't have this skill. Either someone taught the barbarians how to refine poison, or this poison was refined in Da Cheng before being sent out."

Regardless of the reason, it all means one thing: there is a deeper, more secretive, and more deadly connection between that hand and the barbarians beyond the Great Wall than the leak of military supplies.

While the barbarians benefit from leaking military supplies, the defenders of Dacheng, at most, will suffer from lack of food and weapons, making the battle more difficult. However, poisoning the weapons and specifically targeting the defenders is a way to break the backbone of this border pass from within, one branch at a time. Once the city walls are undefended, it will be like opening the gates to thieves and letting wolves into the house.

This connection is ten times more dangerous and insidious than simply colluding with the enemy to amass wealth.

"Following this arrowhead, we can trace it." Yang Hu's fingertips slowly caressed the cold arrowhead. "Arrowheads are standard military equipment, with their own regulations. We can find out which armory it came from, which batch it was issued in, and who signed the document. We can check the records to find out."

He paused, then continued, "And there's this poison. I've practiced medicine for many years and know the properties of hundreds of herbs. Whether the poison on the arrow is from common plants within the pass or a rare poison only found outside the pass, I can tell about 70-80% of the time by the lingering fishy smell and medicinal properties. Where the poison came from is another clue."

A doctor can distinguish medicine as easily as he distinguishes poison. His skill in testing poisons has now become another knife in his hand to cut through the fog of mystery.

He raised his head and looked out the window at the heavily lit central command tent.

"The more he stretches his reach, the more clues he reveals. A single arrow that slips through the cracks becomes a thread that leads to the discovery of the whole thing."

Qin Ying looked at him quietly.

This young man in his early twenties, facing the overwhelming force that could only cause a border post to fall and millions of soldiers to become skeletons, showed no fear in his eyes, only the calmness of a hunter eyeing its prey.

Outside the tent, the fighting on the city walls continued unabated; inside, there was a solitary lamp, a poisoned arrow, and two people who would try to shake the overwhelming dark hand with their own strength.

"Aren't you afraid?" she couldn't help but ask softly. "Having investigated this far, you already know that what that hand wants is the heinous crime of overthrowing a country. Such a person wouldn't even blink an eye if they wanted to harm you."

Qin Ying was asking the truth. Having investigated this far, the sinister face of that hand was gradually being revealed. It was no longer just a corrupt parasite, but a colossal villain who dared to use the entire border region and millions of lives as bargaining chips. To be an enemy of such a person was to risk one's life.

"I'm afraid," Yang Hu admitted frankly, but his gaze remained unwavering. "But behind this barrier are millions of civilians. If this barrier is breached and the barbarians' iron hooves trample in, it won't just be these dozen or so soldiers on the city wall who die, but countless innocent people inside the pass."

He paused, gazing out the window at the heavily lit central command tent, his voice softening yet carrying immense weight.

"A doctor's heart is like a parent's. This poisoned arrow poisons the blood of a soldier; but the hand hidden in the shadows poisons the bloodline of the entire nation."

"I cured one soldier of arrow poison," he said, emphasizing each word, "and I wanted to try to see if I could cure the 'arrow poison' of this whole country."

Pull out that venomous fang that's buried deep within the flesh, root and all.

Qin Ying stared at him blankly.

At that moment, she suddenly realized that what she was doing by following this person was no longer as simple as clearing the name of the Duke of Lu's entire family and exonerating herself.

What they were trying to pull out was a poisonous fang deeply buried within the very fabric of the nation, enough to kill an entire country.

This venomous fang shattered the loyal bones of the entire Lu family, devoured the lives of the soldiers of this pass, and coveted the vast land of this nation.

Pulling it out would mean certain death. But not pulling it out would mean letting it slowly drain the blood of this nation.

Outside the window, the night was deep. The lights in the central command tent were blindingly bright. The hand hidden deepest within was still dreaming of its grand ambition of dominating the world and inviting wolves into the house, completely unaware that every poisoned arrow it shot was being carefully guided back to its own throat by a pair of calm eyes.

He carefully tucked the arrow into his inner pocket and then wrapped it in oiled paper. This was something he couldn't handle, much less lose.

The arrow was wrapped in two layers of oiled paper and then secured with hemp thread. From this night on, this tiny arrowhead would be the heaviest burden weighing on him.

As the snowstorm approaches, those who walk at night with lanterns have already quietly tightened their grip on the first thread.