While the cutter herself didn’t have much in the way of armaments to take out the Tango-class submarine, they could dog the sub using their sonar until a strike aircraft could be called in from any number of naval air stations. They had come too far to blow it this late in the mission. If it meant an hour or two delay to lurk quietly under the surface until the cutter was out of range, so be it. Patience and silence were the two cardinal virtues of a submariner.

The trip north had taken them more than a week, most of that time spent well outside normal shipping routes and running at snorkel depth so the boat’s three diesel engines could draw air. Only when sonar reported a nearby ship, usually one headed inbound from Asia as they came abreast of ports along the U.S. and Mexican west coasts, would they retract the snorkel and dive out of sight.

While normally crewed by seventeen officers and sixty-one seamen, this particular sub had only two dozen men aboard, and the captain couldn’t have been prouder of them.

“Sonar, sit-rep,” he whispered. He was standing behind the man hunched over the antiquated passive sonar system.

The sailor slipped off the one headphone he’d had plastered to his right ear. “The cutter’s still moving away at eight knots. I put him at five miles distant.”

In relative terms, five miles was a tricky distance. It was only a five-minute drive by car or it was a two-hour walk. At sea, with sound able to travel so far through the vastness, five miles could be considered shouting distance.

“Any indication he’s towing an array of his own?”

“No, sir,” the sailor whispered back. “If he was, he’d cut his engines to drift. Otherwise, he couldn’t hear anything over his own propellers.”

The man suddenly tightened the headphone to his skull once again. It was as if speaking of it made it happen. “Captain! His screws just went silent. He’s drifting!”

The captain placed a restraining hand on the younger man’s shoulders. “Steady, son. He can’t hear us if we don’t make a sound.”

The boy looked sheepish. “Yes, sir.”

“We’re nothing but a three-hundred-foot-long quiet spot in the ocean. Nothing to hear here. Just move along.”

The captain looked across the confined conn. The low-ceilinged room was as claustrophobic as a crypt, and with the red battle lights glowing, the men appeared demonic. In the center of the space the periscope hung from the ceiling like a metallic stalactite. Around it were clustered the helm station, the engineering monitoring space, the captain’s chair, and several other workstations. The sub was so old that all its readouts were on analog displays and simple dials, not unlike those of a World War II — era boat. The air was somewhat chilly, and with the sub running off her batteries, amps weren’t squandered on extra heating. And yet several men still had sweat on their faces. The tension was palpable.

“The cutter is still drifting, Captain.”

“That’s okay, lad. Let him drift. He has no idea we’re here.”

They had been running ultraquiet for the better part of an hour since first detecting and identifying the cutter from a database of acoustic signals stored on magnetic tapes — another piece of antiquated technology that illustrated the Tango-class’s ’70s roots. So when an internal alarm sounded, it was especially shrill and piercing.

The seaman closest to the alarm held true to his training. Most men would have remained frozen for a few crucial seconds as their brain processed the source of the intrusive noise, but he moved with the speed of a cat and hit a toggle that muted the klaxon. Half of the red battle lamps began to pulse as a visual cue that an emergency was under way.

Time seemed suspended as the men exchanged nervous glances. They now faced two dangers: one, the American cutter that had been listening for sounds in the abyss with a towed sonar array that could pick up the slightest anomalous noise — one Cold War story told of how a Soviet sub had been tracked for its entire four-thousand-mile journey because one crewman popped his gum whenever he was alone — and, two, whatever the boat’s sensors had detected was life-threatening enough to warrant a tripped alarm.

The answer to that second danger came moments later when a wisp of smoke coiled from one of the overhead ventilators. Even as the crew turned to watch, that wisp became a white, opaque torrent.

More than drowning, submariners feared fire.

And it was obvious that the boat was burning.

The captain’s gaze swept the bridge, pausing for only the briefest moment on one particular figure before moving on. There would be no help there. He focused on his executive officer. “XO, lock down that fire no matter what it takes. Silence must be maintained.”

“Sir,” the man said, and rushed forward where the smoke seemed to be thickest.

“Sonar, sit-rep?” the captain asked with studied disinterest. He needed to show his crew there was no need to panic. Inside, his guts felt oily.

“Contact still drifting,” the sonarman replied, one hand pressing the headphone so tightly, his fingers had gone white.

“Did he hear us?”

“He heard, all right. He just doesn’t know what he heard.”

“If you were him, what would you do?”

“Sir?”

“Answer me. If you were listening on his passive array and heard that alarm, what would you do?”

“Um,” the sailor hesitated.

“Simple question. Tell me. What would you do?”

“I would turn my ship to our bearing and tow the array once again, hoping to pick up another transient emission.”

The captain knew the correct answer, the one his young sonarman had given, but his instincts told him to abandon the bridge and follow his XO. The fire was the immediate emergency. The American cutter was secondary. And yet training dictated otherwise. He must remain on the bridge. It was a good leader’s ability to acknowledge the disconnect between instinct and training that kept crews alive. The most immediate threat to the sub wasn’t the fire at all. It remained the Coast Guard vessel.

He waited with the rest of his men, his eyes glued to the big clock over the planesman’s station. The cutter continued to drift and listen on her passive array.

At the six-minute mark, he let out a little of the breath he felt he’d been holding since the alarm sounded. At seven minutes, he exhaled the rest.

“I think he’s missed us, boys,” he whispered.

Just then, the XO returned.

“Sir, it was a small grease fire in the galley. Nothing’s been damaged.”

“Captain, the cutter’s engines just came back online. She’s gaining seaway.”

“Is she turning?”

The wait seemed endless, but the young sailor suddenly turned to look at his captain, a big grin splitting his face. “She’s headed due south and is already up to eight knots.”

“Well done, everyone,” the captain said in an almost normal tone of voice. He looked over at the stoic face of Admiral Pytor Kenin. He wasn’t sure what to expect, so he was pleasantly surprised that the man gave him a grudging nod of respect.

Kenin had been leaning against a bulkhead and suddenly pushed himself erect and called out, “Evolution complete.”

The red battle lights clicked off, and overhead lamps bathed the sub’s control room in stark white light. Technicians who’d been unseen moments before entered the space to check on equipment, while the sailors manning the various stations got up from their seats. Their bodies were as exhausted and tensed up as if this had been a real encounter and not a training exercise. And yet there was a feeling of self-satisfaction among them for a job well done.

“Congratulations, Captain Escobar,” Kenin said when he reached the man’s side, a hand extended for a shake. He spoke English, the only language the two men shared.

“For a moment I thought we had failed,” Jesus Escobar admitted. “A most inopportune time for a simulated fire.”