The Grand Duke's Son Is A Heretic-Chapter 511

Elliot paused and took a careful look ahead.

Frail shadows stretched along the tunnel walls, and as the shapes moved closer, a blurry dark mass formed in the dim light.

"It seems the intel was right," Elliot whispered. "This place has completely been taken over by the Abyssal Sect."

He glanced at the others, his face tense.

"The nobles and knights might have rebelled and been imprisoned. In their place, these abyssal demons are guarding everything."

"Let’s take them out," Kael said quietly, and stepped forward with the others.

The canal tunnel felt suffocating. Black water flowed slowly beside the narrow stone path. The walls were damp, covered in moss and strange dark veins that pulsed faintly like living things. A foul smell hung in the air.

Lowering himself to his haunches, Kael readied his fists. His body tensed, and then he closed the distance in a blur, moving straight toward the nearest abyssal soldier.

The demon felt something wrong and turned around.

SWOOSH.

It looked left and right, confused, muttering strange words.

"KUR... kumk..."

It was about to step forward when two hands shot out from the darkness, grabbed its head, and twisted hard.

CRACK.

Its neck spun around unnaturally, and the head separated from the body. The corpse dropped without a sound.

The others moved at the same time.

One assassin slid low and cut behind a demon’s knee. As it fell, a blade went through its throat. Another warrior drove his sword straight into a demon’s chest, then twisted and pulled it out in one motion.

Dark blood splashed on the stone floor. The air grew hotter as the demons’ bodies released a faint burning smell.

But in the chaos, one knight dragged down a demon near the edge of the sewage channel. He did not notice the position.

The corpse slipped.

SPLASH!

It fell into the dirty water with a loud, wet sound that echoed through the tunnel.

Everyone froze for a breath.

"Hiss... Damn..." someone muttered.

From deeper inside the canal, low growls answered.

A wave of abyssal demons began rushing toward them, claws scraping against stone.

One leaped at Kael.

Before the claws could hit, Kael spun and kicked.

THUD.

The demon’s ribs collapsed inward, and its body slammed into the wall. It slid down and stopped moving.

After confirming it was dead, Kael moved to help the others. Blades flashed again. Fists struck. The narrow path filled with broken bodies and dark blood.

Moments later, the last demon fell.

They stood among the corpses, breathing heavily.

"This tunnel links to the palace foundations," Elliot said in a low voice while stepping over a broken grate. "We are almost under the inner district."

Behind them, Ruth’s explosion continued to echo through stone like distant thunder. Each shockwave made dust fall from the ceiling.

Just then Kael suddenly stopped and raised his hand.

"Stop. I have something."

Elliot frowned. "What do you have?"

Instead of answering, Kael reached into his coat and pulled out a folded parchment. He opened it carefully despite the wet air.

It was a construction map.

Lines, corridors, underground routes, and marked structures were drawn in detail.

Everyone leaned closer.

Martina’s eyes widened. "Where did you get that?"

Elliot looked irritated. "If you had this, why didn’t you tell us earlier?"

For a moment Kael had no words. He clicked his tongue softly.

"I got it only a little while ago," he said. "I am not even sure it is correct. I took it from one man I dismantled in the eastern battle."

Elliot stared at him. "If you are not sure, why show it now?"

"So we can compare the structure and see if it matches this place," Kael replied calmly.

That made sense. The tension eased slightly.

Martina took the map and crouched. Elliot bent beside her. The two began checking the tunnel walls, drainage slopes, and support pillars.

"Look," Martina said, pointing at the drawing. "This curve in the sewage line. That matches this bend."

Elliot nodded. "Yes. Then we are directly under the kitchen sector."

He traced a line further. "This side passage leads to the dungeon below the Imperial Palace."

Kael looked ahead into the dark corridor. "And if we follow this main line?"

"We reach close to the throne hall foundations," Elliot answered.

"We do not need to go to the throne hall," Kael muttered.

Martina’s expression hardened. "We need the King’s chamber. That is the target."

They continued whispering directions, matching turns and distances.

As they planned, Ruth’s presence behind them suddenly grew sharper.

He had been silent, but now he spoke.

"I think we should divide."

Elliot looked up. "Divide? For what?"

"One group should go toward the dungeon and check if people are locked there," Ruth said calmly. "If they are nobles, we can negotiate. Then we can gain help and increase our chances."

Elliot hesitated. "It is risky. Very risky."

"But it might work," Ruth replied. He slowly drew his sword.

Seeing that motion, Martina felt a chill. "Kael, what is he going to do?"

"How would I know," Kael whispered back, though his eyes were already sharp.

Ruth turned toward the deeper, darker tunnel where growls echoed.

"I am not going to move silently."

Elliot frowned. "Then?"

"I will make heavy noise and draw attention," Ruth said. "You move ahead. Ramos will sense the aura and make a move too."

He lowered his stance slightly. The faint green glow of moss on the tunnel walls reflected along his blade. The sewage water beside them rippled even though nothing touched it.

Far away, more demonic sounds rose.

"Till then," Ruth said quietly.

The next instant—

BOOOOOOOOOOOOM!

A terrifying burst of power exploded from him. The tunnel shook violently. Cracks ran across the ceiling. Dust and small stones rained down. The black water splashed high against the walls.

The quiet sewer had turned into a battlefield in a heartbeat.

Demonic roars answered from every direction.

The ground ahead suddenly collapsed inward as the force of battle above and behind them shook the underground network. Loose bricks broke away, and a section of the sewage tunnel caved in. Filthy water rushed forward, carrying broken stones, bones, and pieces of abyssal bodies that had been cut apart earlier.

The sewage reached their calves. The smell was suffocating, thick and rotten, and the air felt heavy in their lungs. Rats scattered along the walls. Old iron pipes dripped black water from above.

Elliot grabbed the map and stood. "Move now!"

Kael grabbed Martina’s wrist and pulled her aside just as a chunk of stone smashed down where she had been standing. The group quickly steadied themselves and pushed forward through the half-flooded tunnel.