The weapon passed underneath the Russian submarine once, without the arming mechanism being triggered.

Serebnitskiv could hear the pinging of the onrushing ADCAP through the hull, even without the aid of sonar. There was nothing to worry about. It couldn’t find them up here in the midst of all this ice. It would soon fly harmlessly by and eventually explode into the bottom when it ran out of fuel.

The ADCAP circled around and came back again, but shallower this time. The arming mechanism still saw the Volk plainly.

It sent an electric pulse to the firing mechanism, which detonated the firing squib.

The firing squib set off the six-hundred-fifty-pound PBNX warhead just as the ADCAP was beneath the sub’s operations compartment.

The vicious shock wave tore through the double hull as if it were little more than tissue paper. Most of the superheated gas bubble vented through the rent in the sub’s bottom, incinerating most anything it touched as it ripped and tore through bulkheads.

The crew members on the Volk had less than a millisecond to realize what had happened. Igor Serebnitskiv was thrown violently upward and across the control room. He had no chance to grab anything. He was brutally impaled on a protruding valve stem, high up on the outboard bulkhead.

Admiral Alexander Durov’s nephew died instantly.

Even if the catastrophic explosion had not been enough, the expanding gas bubble it set off lifted the Volk upward like some child’s toy and crushed it against the ice pack above.

Smashed and mortally violated, the mangled, lifeless hulk sank to the bottom of the cold, cruel sea.

“Torpedoes passed astern!” Tommy Zillich yelled as he listened to the headset, his hands pressing the earpieces closer to his ears so he could hear everything going on out there. “We may be clear!”

Toledo was still angling sharply downward, toward the bottom, racing to get clear of the Russian weapons. They had all heard the deep rumble of the other submarine as it exploded. Now the control room was silent, everyone listening for the high-pitched scream of the incoming weapons.

That sound, as all the men aboard knew, would signal their immediate death.

A few of them breathed a sigh of relief when they heard Zillich’s report. Glass knew better. They weren’t free yet. Those two torpedoes were still out there, still searching doggedly for them.

The sonar man confirmed his worst fears.

“Torpedoes! Both coming out of the baffles!” Zillich yelled over the 7MC. Now he had lost his calm demeanor. His voice was high and strained. “They’re closing!”

The Russian weapons had crossed astern of them and then turned back, looking once again for Toledo. They were both still relentlessly coming after them.

“COB, get me thirty feet off the bottom!” Glass ordered Sam Wallich. “Do it now!”