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.