Chapter 1 — The Cable Splicer Beneath the Sea

Signal Breaks at Midnight

At 1:47 a.m., Vũ Thanh Sơn squatted on the back deck of the Vạn Lý, his hands tracing every centimeter of the orange safety rope that had been rolled up after the previous afternoon's maintenance shift. High-powered headlights hanging from the crane cast a white halo, attracting moths around his face. Sơn did not chase them away. He was counting the turns of the wire and checking each metal joint with his thumb, just as he had six hours earlier—and would do again before morning.

"Mr. Sơn, I tested the load this morning. It's all within standard." Kiều Xuân Bách walked out of the technical compartment with two cans of energy drink and tossed one towards Sơn. "Checking it three times a night is a bit much."

"Four." Sơn picked up the can of water without looking up. "This time is different, last time I checked it while it was still drying. Now it has just finished soaking in sea water."

Bách shrugged, sat down next to the pile of rope, and didn't argue any further. He had been on the team for two years—long enough to know that arguing with Sơn about equipment was useless, but not long enough to understand why a man once called “the toughest diver in Vũng Rạng waters” now spent half the night counting rope twists.

The sound of urgent footsteps on the iron stairs interrupted the story. Tô Gia Bằng rushed out of the ROV control room, his T-shirt still askew, his laptop tucked under his arm, his face paler than usual under the yellow light.

"Line LH-CN1 just lost signal completely," Bằng spoke in one breath, unable to catch his breath. "NOC called me three minutes ago. All traffic from Cồn Nga to the mainland dropped to zero at one forty-two."

Sơn stood up, the seat belt still wrapped around his wrist. "Complete breakage or deterioration?"

"Completely cut off. There is no response signal at the other end, and no traffic is getting through. NOC tried rerouting through a backup satellite, but its bandwidth is enough for only a few emergency voice calls—not for the banks, hospitals, or the island's automatic weather-warning system."

Bách stood up suddenly, the can of energy drink in his hand was distorted. "This time? Right when storm number nine is strengthening?"

No one answered that question, because the answer was already in all three people's minds. Sơn looked towards the command post, where the cockpit light had just turned on. Captain Phạm Vũ Hòa had woken up.

Ten minutes later, the entire technical team stood around the chart table in the cockpit, where Hòa was opening the latest forecast bulletin. On the screen, a gray-white vortex curled offshore; its projected path was a red strip crossing the exact area where the LH-CN1 cable lay.

"Storm number nine, wind speed level eleven, moving west-northwest, speed twenty kilometers per hour." Hòa read it out loud, with a monotone voice like reading a normal weather report, although everyone understood that it was not normal at all. "According to current forecasts, the center of the storm will pass through this sea in the next seventy to seventy-two hours."

"Seventy-two hours," Bách repeated, as if saying the number out loud would make it less scary. "How long does it take to repair a normal broken cable?"

"If the break is near shore, the water is shallow, and the weather is good, it takes a day and a half—sometimes two days—including locating the fault, hauling up the cable, splicing it, and testing the signal," Sơn answered, eyes fixed on the storm's projected path. "But I don't know where the break is or how extensive the damage is. It could be a clean cut from a fishing-boat anchor, or an entire section crushed against a reef."

The satellite phone on the chart table rang and the blue light flashed. Hòa picked up the phone and turned on the speakerphone.

"Captain Hòa, I am Nghiêm Việt Trung, regional technical director of Liên Hải." The man's voice on the other end of the line was as tense as a guitar string, without a second of welcome. "I need your team to depart tonight. We just lost complete connection to Cồn Nga, and according to the latest storm forecast, we only have a very narrow weather window left before that area is closed to any ships."

"I saw the forecast, Mr. Trung," Hòa replied in his familiar calm tone. "But I need the exact location of the break before deciding our route and sailing time. Setting out without clear coordinates would waste the weather window, not use it."

"I will send preliminary coordinates in five minutes, calculated from the OTDR data at the land station," Trung spoke quickly, clearly prepared. "I know you need time to confirm, but understand this: if the line is not reconnected before the storm arrives, more than four thousand people on Cồn Nga will lose high-speed communications. No automatic warnings, emergency app calls, banking transactions, or remote hospital consultations. There are only a few backup satellite voice calls, and that bandwidth cannot meet even one percent of the island's needs."

Sơn looked at the clock on the cockpit wall. The second hand ran steadily, indifferent to the seventy-two hours mentioned three times in the past ten minutes.

"We will set sail as soon as we have the coordinates," Hòa said, looking straight at the phone speaker as if looking straight at Trung. "But I'm not going to push my team of divers underwater in unsafe conditions just because the clock is running. You need to understand, a wrong decision on the ocean floor can't be fixed like a line of code."

The other end of the line was silent for a beat. "I understand, Captain. I won't ask you to do anything unreasonably dangerous. I just need you to understand the true level of urgency on my end."

The call ended. Bằng opened his laptop and typed continuously to download the OTDR data sent. Sơn stood still for a moment, his hand unconsciously touching a small metal link worn on his wrist, under the diving watch. It was a habit he didn't realize he was doing, until Minh Thư, a young technician who had just boarded the ship this afternoon, entered the cockpit with a sleepy expression while trying to appear alert.

"I heard the alarm, what's going on?" Thư asked, her eyes still glued to the storm forecast screen displayed on the large board.

"The lifeline cable of an island just broke, just as a storm was coming," Sơn answered briefly, without any drama in his voice, as if announcing that the lunch hour had changed. "And this is my first trip to sea."

Thư gulped, looked around the cockpit, from Hòa's tense face to Bằng's constantly typing fingers, then stopped at Sơn - the only person in the room with a strangely calm appearance, even though his hand was still clutching the orange seat belt as if it was the only thing keeping him standing.

Three minutes later, coordinate data sent from Trung appeared on Bằng's screen: a point about eighteen nautical miles from shore, located on the LH-CN1 cable line, estimated depth of seventy to ninety meters.

"The accuracy of these coordinates is only approximate." By typing a few more commands, zoom in on the signal loss graph displayed as a curved red line. "OTDR measures light reflection along the cable, calculating the distance from the docking station, but the error can be up to several hundred meters, especially if the cable was bent abnormally before breaking. I still need the ROV to reconnoitre the field to determine the exact point."

"So that means getting there still takes more time to search, not including the time to fix it," Thư spoke, her voice a bit confused, as if she was rearranging her entire vision of the job she had just started studying.

"That's right." Sơn looked at her, his eyes not showing any false reassurance. "There is no magic in this profession that can shorten physics. Wherever the cable breaks, we have to find that exact place, go down to that exact depth, endure that exact pressure. There are no shortcuts."

Bách finished putting on his rubber boots and checked the shift roster posted on the wall of the technical compartment. "Mr. Bằng and I prepared the ROV first and started the DP as soon as we left the port channel. Where is Ms. Lam?"

"She's checking the decompression chamber, preparing for a saturation dive as soon as she gets there." A female voice rang out from the cockpit door. Chu Tuệ Lam walked in, holding a medical file in her hand, her face expressionless. "I took note of the physical condition of all the divers in the team, including the new ones." She glanced briefly at Thư, then turned to Sơn. "Are you still at the same resting heart rate as last month?"

"Still the same," Sơn replied, not avoiding the question, although everyone in the room understood that it was not just a question of physical health.

Hòa tapped lightly on the chart table, signaling the end of the meeting. "Preparing to leave port." He ordered, his voice decisive, leaving no room for hesitation. "All crew in position in twenty minutes."

Outside the cockpit window, the night sky was still clear, stars peeking out from behind a few thin, slow-moving clouds - the last peaceful light before the number nine storm began to cast a shadow over the entire journey ahead.