Seo-joon returned to the shrine with blood on his lip and three days left to live freely.
Mak-bong saw him first.
The boy jumped up from the broken steps. "What happened?"
Min-seo stood behind him, her basket still in her hands. Her mother, Han Yeon, looked up from the corner with tired eyes.
Old Lady Wol entered behind Seo-joon and struck her stick against the wooden floor.
"He challenged Gu Chil in Deok-su's own house."
Mak-bong went pale. "You what?"
Seo-joon wiped his mouth with the back of his hand.
"I made an offer."
Min-seo's eyes sharpened. "And the blood?"
"Part of the negotiation."
No one laughed.
Seo-joon walked to the center of the shrine and sat down. His stomach still ached where Gu Chil had punched him, but pain could wait.
Three days.
That was not much time.
He had made a dangerous accusation without proof. In modern life, proof meant bank records, cameras, documents, receipts. Here, proof was harder.
But not impossible.
Money still moved.
Men still lied.
Weak systems still leaked.
Seo-joon looked at everyone.
"Gu Chil is probably stealing from Deok-su."
Mak-bong lowered his voice. "Probably?"
"Yes."
Min-seo's face tightened. "You accused him with probably?"
"I accused him because probably was enough to make Deok-su curious."
"And if you're wrong?"
Seo-joon looked at her.
"Then I lose."
The answer settled over the shrine like cold smoke.
Han Yeon coughed softly from the corner.
Min-seo's hand tightened around her basket.
Old Lady Wol sat near the entrance. "Deok-su gave him three days. If he fails, Deok-su takes him and the business."
Mak-bong whispered, "Takes… us too?"
Seo-joon did not answer immediately.
That was answer enough.
Min-seo stepped forward. "You risked us?"
Seo-joon met her eyes.
"Yes."
Her expression hardened.
"I didn't agree to be gambled."
"No. You agreed to work in a slum controlled by men who already gamble with your life."
"That doesn't make you better."
"I'm not trying to be better."
Seo-joon stood, slowly, ignoring the pain in his stomach.
"I'm trying to make sure the hand around our neck belongs to me instead of Gu Chil."
The words were ugly.
Honest.
Min-seo stared at him with open disgust.
Mak-bong looked scared.
Old Lady Wol smiled faintly, but there was no warmth in it.
"At least the boy knows what kind of monster he's growing into," she muttered.
Seo-joon turned toward her.
"Can you still sell today?"
Old Lady Wol raised an eyebrow.
"You got punched, threatened, and possibly enslaved, and your first question is sales?"
"My first question is cash flow."
Mak-bong frowned. "What's cash flow?"
"Breathing for business."
Seo-joon crouched and drew three lines in the dirt.
"Day one. We make Gu Chil move. Day two. We trace the money. Day three. We place proof in front of Deok-su."
Min-seo crossed her arms. "And how do we force Gu Chil to move if Deok-su told him not to touch us?"
Seo-joon looked at her.
"By making him think we're weak enough to rob and rich enough to bother."
By midday, the plan began.
Old Lady Wol returned to the market with a smaller supply of soft porridge roots. Only eighteen.
Enough to look like business was struggling.
Min-seo took twelve for quiet delivery.
Mak-bong spread whispers through the alleys.
The root business was scared.
Seo-joon had angered Deok-su.
Gu Chil would soon crush them.
People believed it quickly because it sounded reasonable.
Fear was always easier to sell than hope.
Seo-joon stayed hidden near the pottery stall, watching the market through gaps between stacked jars.
Gu Chil appeared after the noon rush.
He did not come close at first.
That was expected.
Deok-su had told him not to touch Seo-joon's people.
But men like Gu Chil hated being told no. They heard limits as insults.
He stood across the road, eyes following Old Lady Wol's mat.
Then he sent the thin man.
The same one who had followed Seo-joon before.
Seo-joon's lips curved faintly.
"Good."
The thin man approached Old Lady Wol and crouched beside her.
Seo-joon could not hear everything, but he saw the shape of it.
The threat.
The hand.
Old Lady Wol looked annoyed, then afraid.
Good acting.
She handed over a small pouch.
The thin man tucked it into his sleeve and walked away.
Mak-bong, hiding near a vegetable cart, looked toward Seo-joon with wide eyes.
Seo-joon gave him the smallest nod.
Follow.
Mak-bong slipped into the crowd.
Now came the dangerous part.
The pouch Old Lady Wol handed over held five mun.
Not ordinary coins.
Seo-joon had marked each one.
Not with obvious scratches. That would be stupid.
He had rubbed soot and rice paste into tiny grooves near the square holes, then wiped the surface clean. To most people, they looked normal.
But if touched with damp fingers, the hidden black paste would smear.
A crude tracking method.
Not perfect.
But enough.
Modern fraud investigations used marked bills, audit trails, controlled transactions.
Joseon had no marked bills.
So Seo-joon made marked coins.
Mak-bong returned an hour later, breathless.
"He went to Gu Chil."
Seo-joon pulled him behind the shrine wall.
"And?"
"Gu Chil took the pouch. Then he laughed. Then he gave the thin man one coin back."
"Did he go to Deok-su?"
Mak-bong shook his head.
"Not yet. He went drinking."
Seo-joon's eyes darkened.
Perfect.
Risky, but perfect.
"Where?"
"Behind the laundry houses."
Yun Dal-rae's place.
Seo-joon stood.
Min-seo appeared from the alley with her empty basket. "What happened?"
"Gu Chil took bait."
She looked at Mak-bong, then Seo-joon.
"You used Old Lady Wol as bait?"
"Yes."
"And if Gu Chil hurt her?"
"He didn't."
"But he could have."
Seo-joon stepped closer.
"Everything could happen. That's why we plan for what happens most likely."
Min-seo's jaw tightened.
"You sound like you're trying to make fear into math."
Seo-joon paused.
That sentence hit closer than he expected.
Then he said, "Fear becomes easier to use when it has numbers."
Min-seo looked away first.
She hated that answer.
He knew.
But she was still there.
Yun Dal-rae's gambling den was louder than before.
Men crouched under hanging sheets, dice clattering inside wooden bowls. Rice wine smell mixed with sweat and steam.
Gu Chil sat near the center, red-faced and smiling too widely.
A small pouch rested beside his knee.
Seo-joon saw it immediately.
Dal-rae noticed Seo-joon entering but did not greet him.
Smart woman.
Seo-joon stayed near the edge with Mak-bong and Min-seo behind him.
Gu Chil threw dice.
Lost.
Cursed.
Threw again.
Lost again.
Dal-rae leaned over and collected coins from the mat.
One coin slipped from Gu Chil's fingers and rolled toward Seo-joon's foot.
For one second, the room seemed to hold its breath.
Seo-joon crouched and picked it up.
Gu Chil looked over.
Their eyes met.
The scar on Gu Chil's cheek twisted.
"You."
Seo-joon lowered his head slightly and held out the coin.
"Your money."
Gu Chil snatched it.
His fingers were damp with wine.
A black smear appeared across his thumb.
Seo-joon saw it.
Dal-rae saw it.
Min-seo saw it too.
Gu Chil did not.
Seo-joon stepped back.
Not yet.
One smeared coin was not enough.
He needed witnesses.
He needed pattern.
He needed Kang Yul.
Seo-joon turned to Dal-rae.
"Is he paying his old debt tonight?"
Dal-rae smiled lazily.
"If he wins."
The gamblers laughed.
Gu Chil stood suddenly.
"You think I'm funny?"
The laughter died.
He pointed at Seo-joon.
"You think Deok-su will protect you forever?"
Seo-joon kept his voice calm.
"Three days is not forever."
Gu Chil stepped toward him.
Min-seo moved slightly behind Seo-joon, but she did not run.
Mak-bong did.
Only three steps.
Then he stopped, ashamed.
Gu Chil leaned close.
"You're dead after this."
Seo-joon looked at the black smear on his thumb.
"Maybe."
Gu Chil shoved him hard.
Seo-joon fell against a wooden post, pain flashing through his ribs.
Still, he smiled.
Gu Chil noticed too late.
"What?"
Seo-joon's voice was quiet.
"You touched me."
The room shifted.
Deok-su had told Gu Chil not to touch his people.
And here, in front of gamblers, Dal-rae, Min-seo, and half the laundry alley, Gu Chil had done it anyway.
Gu Chil's face tightened.
Then he laughed loudly, trying to bury the mistake.
"He fell. Everyone saw."
No one answered.
Dal-rae picked up her dice bowl and shook it slowly.
"I saw many things tonight."
Gu Chil glared at her.
Seo-joon wiped dust from his sleeve.
Then he bowed slightly.
"Enjoy the game."
He left before Gu Chil could decide whether anger was worth disobeying further.
Outside, Mak-bong grabbed his sleeve.
"That's proof, right?"
Seo-joon shook his head.
"No. That's pressure."
Min-seo walked beside him silently.
After a while, she said, "The coins worked."
Seo-joon glanced at her.
"You noticed?"
"His thumb."
"Good."
"Is that enough?"
"No."
Her face tightened.
"Then what now?"
Seo-joon looked toward Deok-su's house in the distance.
"Now we make Kang Yul want the truth."
At dusk, Seo-joon waited near the road where Kang Yul passed after collecting market tallies.
He did not jump out.
He did not beg.
He stood where he could be seen.
Kang Yul noticed him and stopped.
"You are either brave or eager to die."
Seo-joon bowed slightly.
"Neither. I have information."
Kang Yul's eyes remained flat.
"Information without proof is noise."
Seo-joon held out his hand.
In his palm was one coin.
A marked coin.
Old Lady Wol had kept one back from the pouch before handing the rest to Gu Chil's man.
Seo-joon had planned that too.
Kang Yul looked at it.
"What is this?"
"A coin prepared this morning. Five like it were paid to Gu Chil's man."
"Prepared how?"
"Wet your finger and touch the groove."
Kang Yul hesitated, then did it.
Black paste smeared his fingertip.
His eyes sharpened.
Seo-joon continued, "Tonight, Gu Chil gambled with coins from that pouch before reporting to Deok-su."
Kang Yul said nothing.
"Dal-rae saw. Her gamblers saw. He also touched me in public after Deok-su ordered him not to."
Kang Yul wiped his finger slowly.
"You are trying to use me."
"Yes."
The honesty made Kang Yul pause.
Seo-joon stepped closer.
"But if Gu Chil leaks money, he makes your ledgers false. If your ledgers are false, your value to Deok-su falls."
Kang Yul's expression changed for the first time.
Not much.
But enough.
Seo-joon had found the right nerve.
Bookkeepers did not care about justice.
They cared about records.
Control.
Being necessary.
Seo-joon lowered his voice.
"I don't need you to trust me. I need you to audit him."
Kang Yul stared at the marked coin.
Then he closed his hand around it.
"One day," he said.
Seo-joon's heart slowed.
Kang Yul continued, "Tomorrow, I will ask Gu Chil for today's collections. If those coins are missing, I will know."
"And Deok-su?"
Kang Yul looked at him coldly.
"Do not speak his name like you stand beside him."
Seo-joon bowed.
"Of course."
Kang Yul walked away.
Mak-bong emerged from behind a wall after he disappeared.
"Did we win?"
Seo-joon looked at the darkening sky.
"No."
Min-seo stepped beside him.
"But we finally made someone important curious."
Seo-joon glanced at her.
For once, there was no disgust in her voice.
Only understanding.
He looked toward the gambling houses.
Gu Chil had taken the bait.
Kang Yul had the coin.
Dal-rae had seen the smear.
Old Lady Wol had played her part.
The first thread was tied.
But a thread was not a rope.
And Gu Chil was still breathing.
Seo-joon turned back toward the shrine.
"Tomorrow," he said, "we tighten it."