“Perhaps we should just remain slow throughout the transit to avoid detection,” Gao said.
“No, Gao. I understand the trade-offs, but I desire to violate Japanese waters for the smallest amount of time as possible. We stay at four knots for the next hour. Then, we accelerate and take our chances.”
An hour later, Chan checked his chart.
“All ahead flank,” he said. “Make turns for twelve knots.”
The submarine shook while laboring. Human noise ebbed in the control room, save for an occasional cough and clearing of a throat while the Romeo passed over the suspected Taiwanese hydrophone array.
As the crosshair passed over the array’s line, Chan noticed the tight, arc-sided triangular intersection between the Japanese territory boundaries and the Taiwanese hydrophone system. For a moment, he violated one neighbor’s waters while exposing his acoustic presence to the hostile renegade province.
His fears chided him into speculating that he undertook a suicide mission. Though he conceived no strategic value in his demise, a skilled politician may have arranged the sinking of his North Korean submarine in Japanese waters to forward an agenda beyond Chan’s sight.
He swallowed as the submarine reentered international waters and slipped into the Pacific Ocean. As he reached his desired distance from the strait, he relaxed his grip on the navigation table.
“Slow to four knots,” he said.
“We have thirty percent battery, sir,” Gao said.
“Excellent. Take us to snorkel depth and charge the battery. Get a fix and seek new radio traffic. I’ll be in the engineering spaces.”
Chan walked aft toward the engine room and passed a whirring propulsion motor, sealed reduction gears, and the length of the starboard shaft. Surrounded by duct tape, extension cords, and laptops on plywood shelves, a lone sailor crouched over a computer.
Chan crouched beside his cryptology ace.
“How’s your progress?” he asked.
Color flush in his cheeks, the sailor looked up.
“Good news, sir,” Park said.
“You see evidence of our rescue ship?”
“That’s not what I meant, sir, but I am breaking the codes to the seven ships you thought might be serving as our rescue ship. I expect to start reading their messages in about eighteen hours, on average, as I break each code. I can go faster on select ships if you let me work my algorithms in parallel.”
“No,” Chan said. “That’s fine.”
A younger sailor walked to Chan.
“Sir, the executive officer reports no new message traffic and requests permission to descend from snorkel depth when the batteries are charged.”
“Permission granted,” Chan said.
The sailor departed.
“This leaves you with no new data,” Chan said.
“That’s okay, sir,” Park said. “That’s the good news. I’m confident I can predict the behavior of the random-number-generating algorithms used by the computers behind the broadcast messages we’re interested in.”
“You’re certain?”
“Just minutes ago, I cracked the code for an East Sea Fleet Kilo submarine, hull three-six-six.”
“Show me.”
Park twirled his laptop, and Chan devoured a secret message intended for his compatriot. The news astounded him.
“The Kilo is also heading to the eastern side of the Japanese islands.”
“I didn’t recognize the numbers as coordinates, sir.”
“That’s what they are,” Chan said. “Whatever our mission, we are part of something greater. We are not alone.”
“That’s encouraging. Right, sir?”
“Yes, Park,” Chan said. “Can you break more of these, for other submarines?”
“Of course. It’s just a matter of time.”
“What about that garbled text?”
Chan pointed at the screen.
“It’s a third layer of encryption. Probably a brief note for just the commanding officer.”
“Can you break it?”
“That would exhaust my resources,” Park said.
“Can you break the second layer for the East Sea Fleet submarines first and then break the third layer for the one that will be stationed closest to us?”
“I can, sir, if you let me know which one will be the closest to us.”
“Consider it done, Park,” Chan said, “as soon as I know.”
As he walked forward, he thought he heard an unfamiliar low-frequency drone. The sound perplexed him, and he flagged his memory to ask his executive officer to check the ship for a sound short. There would be disciplinary action if a sailor had left a tool connecting a loud machine to the hull, bypassing sound isolation mounting.
His eyes wide, Gao met him at the navigation chart.
“Sir, active intercept, two hundred hertz.”
“No ship uses a sonar frequency that low,” Chan said.
“I know, sir.”
“Do you have a bearing?”
“It’s vague, sir. At best within ten degrees, it’s roughly coming from the west. We’re also catching reflections from the southwest at lower power.”
“Reflections from what, Gao?”
“That’s the problem, sir. There’s nothing out there for the sound to reflect from, unless there’s a nearby submarine.”
“Draw the bearings on the chart, Gao. Include the reflections.”
Chan watched his underling brush a pencil over trace paper. An idea formed in his mind, but he hesitated to vocalize it — until he heard the active broadcast again.
“There it is again, sir,” Gao said.
“Same bearings?”
“Same bearings, sir.”
“Secure snorkeling and take us deep,” Chan said.
Chan tapped his fingers on the chart, pondered the incoming sounds, and waited for Gao to reappear.
As the deck leveled, he grabbed a pencil and drew hard lines over the Taiwanese hydrophone system.
“What are those, sir?” Gao asked.
“These are my best estimates,” Chan said, “of the newly discovered Taiwanese active-emission sonar hydrophone array.”
“Active-emission, sir? You think that we’ve not only verified the existence of the Taiwanese hydrophone array, but we’ve learned that it includes an active transmission?”
“Yes, making secret passage over its length nearly impossible,” Chan said. “And this also implicates the Japanese beyond doubt as providing a power source.”
“What do we do, now, sir?”
Chan stepped up to the conning platform and sat in his foldout captain’s chair.
“We clear out of here, pray nobody follows us, and share what we know with the fleet if we survive long enough to do so.”
CHAPTER 24
For the first time, Pierre Renard wished he had been aboard a surface combatant instead of a submarine. He had built the consensus, drafted the plans, and brokered the weapons transactions, but young men on small patrol craft had faced the mortal danger in carrying out his vision, and they had prevailed.
His adrenaline had spiked and then fallen after feeding the egressing squadron the spying Hai Ming’s undersea information. Lifting an unlit cigarette to his lips, he glanced at his console to verify his visual connection with Henri. Crouched in his seat, his countryman rested his sweaty hair in his hands awaiting orders from Keelung.
Renard left Henri unperturbed and stepped to the navigation chart to learn progress aboard the captured mainland Kilo submarine. Admiral Ye’s staff buzzed around the command center churning stolen encryption codes into cracked intercepted mainland message traffic. As an officer rendered his report to Ye and departed, Renard approached his client.