Chapter 17 — The Thirteenth Landmark

The window is not on modern maps. It is a small pipe going under the lake, built before Milestone 13, only used when the main sewers cannot operate. Nam found traces of it in the old blueprint: a thin curve running from the maintenance bay to the north bank, then disappearing under the residential area.

"If this door is open," Nam said, "the water will drain into an underground channel. But the last door is under the old water plant floor."

“The factory is abandoned.”

“On paper.”

Khoi took the group to the factory area by boat. The receding water left behind thick mud, but the low inlets remained filled with water. The rescue team set up flashlights, set up gas meters and checked the anchor ropes.

An brought an old map with a blue ink mark on it that her father once drew. She followed a pipe running under the floor to the room containing the filter. The wall has been painted over many layers. In the corner, a large van wheel is exposed from behind a pile of bricks.

“Window zero,” she said.

The valve has no lock, but the crank handle is welded to death. Nam uses the cutter, Khoi holds the shield. Every time the spark touches the metal, the water under the floor vibrates slightly.

“There is pressure on the other side,” Khoi said.

An looked at the clock. "It's not water. It's gas."

A chemical pipe connects to the valve, which is not included in the design. If cut incorrectly, toxic gas will flood into the room.

“Tan Giang uses factories as warehouses?” Bich asked.

“Or they use old pipes to hide waste,” An said.

Nam opened the inspection box and found three compressed air cylinders and a sensor. The sensor screen shows a pressure of 1.3 bar.

“They pump gas to force water to the North Shore,” he said. “Ground neutral is a thruster.”

“So what if it opens?”

“Compressed air repels both water and chemicals.”

“If not opened, the urban area will continue to crack.”

Khoi looked at the map. “You can release the air first, then open the valve.”

“Need to remove the tank in order.”

An reads the label of each bottle. Two jars are numbered 1 and 2, the third jar has no label. On the body of the third vase there is an arc shaped like a ring.

“This bottle belongs to DQD,” Bich said.

Duy stood outside the door and heard. He had taken off his coat, his hands were oily.

“That bottle must not be opened,” he said.

"Why?"

"It contains a corrosion inhibitor solution. If you drop it into the pipe, the valve won't jam."

“You know chemicals?”

“I signed to buy it.”

“So that's all.”

Duy looked at the room and slowly said: "In the past, Tan Giang was established to handle the drainage system. They installed chemical tanks at old points, under the pretense of protecting the pipes. Then they used them to distort the water level. Your father found out, but he only had one night to save the hospital."

Secure the map. “You know but you still continue.”

“I think if the project is completed, the city will have money to fix everything.”

“He thought a lie would end in the truth.”

“I was wrong.”

That was the first time Duy said that sentence without a reason.

An asked him to remove the third tank. Duy made it himself. When the tank valve opened, a pungent odor poured out, but the gas meter remained within limits. Khoi opened the ventilation door, Bich turned around.

Nam cut the sensor wire, An turned the crank. The window is not stuck, then opens strongly. A stream of black water rushed through the floor, carrying white residue with it. Khoi pulled An up the stairs, but Duy slipped.

An grabbed his hand.

“Let go of me!” Duy shouted. “You just let me sink.”

“I don't do it like you.”

Khoi pulled them both up. The water flows into the underground canal, causing the factory floor to vibrate. A section of wall collapsed, revealing an underground room.

In the room there is a blue iron cabinet. An recognized the lock style as the Phan Loc file. She opened it with the key semicircle.

Inside was her father's notebook.

The book cover is wet but intact. The first pages record the water level, pressure and the name of the person on duty. The last page has a payment sheet, signed by Duy and a person named Trang. Next to the amounts are captions: “buy one night”, “close profile”, “switch server”.

An turns over quickly. One page has the line: "I accepted the money, but did not accept the promise to take the blame. If they force me, take An to the south. Don't let her know I signed."

Mrs. Hanh read with her, her eyes turned red.

“You knew he hid the notebook here?”

"I only know there is a notebook. I don't know what it says."

An doesn't blame her mother. She opened the next page and saw a map with three capital letters: “LAST SIGNER.”

Below that is the name Nguyen Dieu Trang, but the signature is crossed out. Next to it, her father wrote: "Trang is not the last person. The last person is the one who has the right to change the name of the stream."

Nam looked at the text. “The person who has the right to change the name of the water stream is the system administrator.”

"Who?"

“The original account belongs to the RiverEye provider.”

Bich opened the laptop. "The supplier has a representative in Ha Luu. Name is Nguyen Minh Tung."

Duy turned away. “Tung has left the company.”

“You know him?”

“He's the one who installed the filter.”

"Where?"

“Old power plant.”

A small explosion echoed from outside the canal. The Milestone 13 signal on the An machine turns black. Milestone 14 is also off.

Nam looked at his watch. “They just cut off the sensor power.”

An closes the book. “So we no longer have measurements.”

Khoi holds a manual ruler. “There are still people.”

Phuc raised the phone. “The resident group still sends in numbers.”

Bich looked at the community data, then said: “The water is rising again, but only in areas with locked sewers.”

An looked at the map. There is a red line running from the old power plant to the Operations Center.

“Tung is holding the filter,” she said. “If we find him, we can find the last signer.”

Duy asked: "What are you going to do with me?"

An put the notebook in his pocket. "You'll come along. You know the system better than anyone."

“I could be arrested.”

"Maybe."

“And if I don't go?”

Khoi opened the boat door. “The water will carry you ahead of us.”

Duy looked at the black channel. The first time he stepped on the boat without a guard.

On the horizon, the power plant horn sounded three times. Not a water warning.

That's the signal someone just turned on the last filter.

The old power plant is no longer a hiding place. When the group left the bunker, reporters stood outside the gate with the investigation force. Bich livestreamed the scene of Trang, Vy and Duy confronting each other under the rescue lights. No one is allowed to leave before handing over the equipment.

Tung continued to decode ministerial accounts. He discovered that the last lock did not belong to Vinh, but was purchased through an intermediary company abroad. The legal representative is a woman named Nguyen Dieu Trang, but the date of issuance of the certificate coincides with the date she was appointed.

“Mrs. Trang created the lock herself?” An asked.

“Maybe. But the key has been transferred to another account.”

“Who accepts?”

Tung opened the log. The recipient name only shows “N-13”.

Nam saw it and stood still. “I once saw this code on your father's computer.”

"Where?"

“In a note about a land broker.”

An opened the book. The page mentions "N-13" but the words are blurred. She used an ultraviolet light to read the rest: "Nguyen Ky Nam".

“Not Hoang Nam,” Bich said. “Nguyen Ky Nam is vice president of Ha Luu Moi fund.”

Vinh is just the person in front. Ky Nam is the one who transfers the money and signs the house contract contractors and buyers of land rights under other people's names.

Duy listened, his face changed color. “He withdrew from the fund two months ago.”

“You knew but didn't report it?” An asked.

“I think he left because of internal matters.”

“People always think everything is internal until water floods into the house.”

Thuan arrived at the scene, requested to preserve the server and block the accounts. He said a search warrant is being sought, but Ky Nam has left the province.

Bich received an email from the scheduled address. The sender is Ky Nam.

“He wants to meet,” she said.

"Where?"

“The old hospital where the generator was saved.”

An didn't want to go, but the email attached a list of money transfers for Thao's family and Bo Bac households. If Ky Nam keeps the original, it could connect the current project with the old flood.

Khoi told the rescue team to come along and keep their distance. They arrived at the hospital in the afternoon. Ky Nam stood under the porch, white hair, thin figure, holding a stick.

“I don't have much time left,” he said.

“What do you want to change?” An asked.

"I want the records to be released after I die. At that time, they cannot force me to change my words."

“You can speak now.”

“Someone is holding my son.”

Khoi looked around and noticed a car parked across the street. Ky Nam gave An a plastic box.

"In here are orders and accounts. I signed many things. I am not innocent."

“But you want to reduce the charges?”

“I want people to know how much they are being exchanged for.”

An received the box. “Where is your son?”

"I do not know."

Bich looked at the car. “Someone is watching.”

Ky Nam suddenly coughed and collapsed. Khoi rushed forward, but he pushed his hand away.

"Don't save me like saving a witness. Save the survivors."

He was taken to the hospital. Inside the box was a list of more than four hundred transactions, each with a fake house code and water level. The largest funds transfer the day before each exercise.

An read the last line: “Cycle 13 — if failed, complete chemical flush.”

She looked up. “They have a plan to fail.”

Nam looked at the screen. “So they were prepared for the sewer not to open.”

Khoi called Bich: "Check the chemical pool. Right now."

Bich opened the map. A red dot flashed under the sample urban area.

“There was a leak,” she said. “The pressure increases.”

An looked out at the riverbank. The water surface is black and does not reflect the hospital lights.

Ky Nam lied about one thing: Ky Nam didn't just want the records to be published after his death. He wanted everyone to have time before the failed plan was implemented.