Chapter 18 — The Thirteenth Landmark

The old power plant is located across the river, abandoned when the city converted to a gas station. Rusted turbines protrude through the corrugated iron roof, while water pipes still operate underground. As soon as the siren went off three times, the entire area fell silent.

Duy stood at the bow of the boat, pointing the way by memory. Without his guardian, he looked much older. An sat opposite, placing his father's notebook in a waterproof bag.

“Where is Tung?”

“Old control room.”

“Are you sure?”

“He likes machines more than people.”

Khoi turned off the engine before shore. The group walked through the factory. The electrical panel has been mostly removed, but a new row of LED lights has been installed on the wall.

“There is backup power,” Nam said.

“Tan Giang cannot use this factory,” Bich replied.

Duy did not speak. He pushed open an iron door, revealing a room full of screens. Nguyen Minh Tung is sitting in front of the control panel, his hair is messy, his eyes are dark. He turned around, not showing any surprise.

“I knew you would come,” Tung said.

“So why not hide?” An asked.

“Because if I hide, they will erase everything.”

Tung turned on a screen. RiverEye shows twelve stations in green, while Markers 13 and 14 are crossed out in red. A new map is being created, naming neighborhoods by project code.

“Are you the last to sign?” An asked.

"My account is the original account. But I did not sign the order to open the sewer."

“I changed the name of the stream.”

"I renamed the sensor according to technical requirements. I think they use it for simulation."

“Do you want to believe too?”

Tung bowed his head. “I deleted a log. Once.”

“Once was enough for the city to be flooded.”

"I know."

Nam approached the screen. “Is cycle 13 task running from this machine?”

“No. It runs from a virtual server, the owner is DQD-01.”

Duy looked at Tung. “Who created the account?”

Tung opened the list. A name line appeared: “NDT-REG”.

Bich immediately recognized it. “Nguyen Dieu Trang.”

Tung nodded. "The account was created using a certificate from the Department of Planning. But the final order was sent from a different key."

“Which course?” An asked.

He opened the log. The string of characters that appears is not the person's name. Tung explained that it is a department-level lock, used to control the system when there is an emergency.

“Who has the departmental course?”

"I don't know. I just know it was activated at a closed meeting."

An looked at Duy. “You know the signer.”

Duy did not respond immediately. He looked at the screen like he was looking at a deep hole.

“The last signer was Nguyen Dieu Trang,” he said. “But the person who made her sign was someone from outside Tan Giang.”

"Name?"

“Le Hoang Vinh.”

Bich was stunned. “Chairman of Ha Luu Moi Fund?”

“That fund holds the land behind Tan Giang,” Duy said. “I'm just the operator.”

“You used the name Tan Giang to cover for Vinh.”

“I use it because I think I can control the consequences.”

An remembers what Duy once said: the city likes to be saved. He truly believes he is the one who can balance everything.

Tung plays a video file. Le Hoang Vinh appeared in the meeting room, white hair, gentle voice.

"We don't need a big flood. We just need a flood deep enough for a report to have a reason. When the North Bank is classified as a reconstruction area, the fund will buy back the land at a subsidized price. Tan Giang builds it, and the city has the budget."

Nguyen Dieu Trang asked: "What if someone doesn't sell?"

Vinh replied: "Water has its own way of persuasion."

Video stops. The room was silent.

An asked Tung: "How long will you keep this copy?"

“Since the day they asked me to delete it.”

“Why only now?”

Tung looked out the window. “For me has a daughter on the North Shore. His house is one of the houses marked in red."

Khoi put his hand on his shoulder. “Give us a copy.”

“I sent it to six places.”

Bich looked at the laptop. “What about mark 14?”

Tung opened the underground floor plan. “It's not just an outlet. It connects to an old silo. This tunnel holds enough water to reduce flooding for the entire North Bank, but the last door is locked by the code of the system's founder."

“My father?”

"Are not. Another person.”

Tung enlarges the code. The digital signature appears on the screen: HN-CTRL.

Nam stepped back. “Impossible.”

“I'm a modeler,” Tung said. “Your code is used to lock the vault.”

An looked at Nam. “You locked it?”

Nam shook his head. “I don't remember.”

“Don't remember or don't want to remember?”

Nam looked at the notebook in her hand. “On the night of the old flood, I entered the code to keep the window in neutral. I think if it opens, the hospital will be flooded. Your father told me to lock it up after he signed.”

“So you're the last one?”

“I am the temporary key holder. But someone used my rights after that.”

Tung shows the history. The code HN-CTRL was activated many times in twelve years, each time coinciding with land transactions of the New Downstream fund.

An sees a clear line between the past and the present. Her father is partly responsible. Nam has some responsibility. Duy, Trang, and Vinh all have parts. No one is alone.

“Can you open the vault?”

Tung nodded. “If we use your father's voice recording and confirm the Nam code.”

“Can you help?”

“I can break the lock, but it will crash the server.”

“Data has been backed up.”

“Let's do it then.”

They went underground. The walkway is narrow, water drips from the ceiling. Tung attaches the wire to the lock set. An plays the recording of her father. Nam stood next to him, reading the confirmation code.

The system asks for the last signer. Tung opens the list, but the displayed name is not Trang or Vinh.

That is: LAM QUANG VU.

An choked. “My father is still the signer.”

Nam looked at her. “Or his account was put on hold after his death.”

“How is that possible?”

“The deed has not been revoked.”

An put his hand on the machine. “If the system needs my father, I will use his records.”

She opened the last file. Mr. Vu's voice rang out in the tunnel:

“I am Lam Quang Vu. I do not allow this water line to be used to force people to leave their homes. If my code appears after September 12, it is no longer my signature.”

Green switch.

The hatch opens. A cold air flowed out, carrying with it the smell of old mud.

Inside is a giant underground lake, still filled with water. On the opposite bank, a pipeline leads directly to the river. If opened, the water will recede from the North Bank.

But on the surface of the lake floats a steel barrel with the New Ha Luu logo.

“What is that?” Khoi asked.

Tung uses a spotlight. The tank holds the dark liquid, with a wire connected to the pressure valve.

An understands: Vinh doesn't just want to create floods. He kept the chemical in the bunker, turning it into a slow bomb.

From behind, a door lock sounded.

Duy is back. “Someone came in.”

The radio screen turned on Nguyen Dieu Trang's voice:

“Miss Lam, I give you ten minutes to leave the tunnel. The door will then be permanently sealed.”

An looked at the black lake surface, then looked at everyone.

“We don't have ten minutes left,” she said. “We have a chance.”

An does not allow anyone to open the tank arbitrarily. They make a list of the order of operations, who holds the rope, who monitors the gas, and who records the time. Bich placed four cameras in the corners of the tunnel, transmitting them out through the hospital's network.

“What if the signal is lost?” she asked.

“Every camera Write it on a separate card,” Bich replied.

Nam checks the primary key. "Ky Nam still has a chemical release code, but it's unknown if he can say it or not."

Trang stepped forward. “I have the code.”

An returned. “You know?”

“I signed the addendum.”

“Then say it.”

The page reads the sequence of numbers. Tung entered, the system responded incorrectly.

“The code was changed,” he said.

Trang looked at Duy. “You changed?”

"Are not."

An understood that Ky Nam had used the real code to lure them into the bunker, and the final code was in someone else's hands.

Restore the pressure gauge. “No time to search.”

An opened his father's notebook. The last page has a water equation and a series of six numbers. She compared the code 319742 at Milestone 13, realizing it was two halves of the same key. The first part is used for equipment, the back part is used for valves.

An enters the range. Open lock.

The chemical tank is divided into three compartments. Compartment one can be discharged into an underground bunker, compartment two must be neutralized, compartment three must be sealed. If you just flush the water, the chemicals will overflow. If held, the pressure explodes.

“The third compartment needs to be moved to the winch,” Duy said.

“The winch was used for steel barrels,” Khoi replied.

“There is an auxiliary winch.”

Duy leads to a small staircase. He knows every valve and every pipe exactly. An watched him operate, no longer looking at the project chairman, but looking at the person who participated in building the system.

“How long have you worked here?”

“Since the lake was still an experimental project.”

“So you know the water will return.”

"I know."

“And you still let them sank the lake.”

Duy shut up. “I think if the project is completed before high water levels, people can live safely.”

“You keep saying ‘if’.”

“Because I don't dare say 'wrong'.”

Khoi and Duy hooked the cable into compartment three. An controls the neutralization valve. Tung monitors gas concentration. Trang stood next to the board, reading each public data.

“Chamber one is safe,” Tung reported.

“Compartment two?”

“Concentrations are dropping.”

A sound of cracking metal rang out. Triple compartment cable slides, barrel tilts.

Khoi rushed forward to hold the hook. Duy followed. An shouted for everyone to move back, but two people were already under the barrel.

“Don't stand there!”

Duy looked up. “If I let go, the barrel falls.”

Khoi tightened the cable. “I won't let go.”

An ran to the auxiliary winch and turned the wheel. The winch is heavy, but each turn lifts the bucket a little more. Bich pointed the camera at all three people.

“Everyone is watching,” she said. “Duy, look at the camera.”

Duy looked up.

“Say it,” An shouted.

He gasped. “Tan Giang used flood data to buy land. I know. I signed the operating contracts. I'm not the only one, but I have a responsibility.”

Khoi continued: "And Mr. Vu?"

Duy looked at An. “He received money to take his daughter out of danger. He signed, but did not sign the plan. We used your signature to cover up the plan.”

The barrel was lifted ashore. Gas concentration decreases.

An did not stop the camera. “Say the name of the person giving the order.”

Duy looked at Trang. Trang looked down at the board. Finally he said: “Le Hoang Vinh and Nguyen Ky Nam. Trang knows, but is not the one who started it."

Trang burst into tears very softly, but still stood at the board. “I know. I signed.”

Signal transmitted out. People, the press and investigative agencies listened to every confession.

An looked at the screen Mark 13. The water level had dropped below 2.5. The real system begins to restore.

A message appeared on Bich's phone: Ky Nam was missing from the hospital.

An understands that the person who gave the last order is still free.