The Alpha abruptly slowed and turned sharply to the right.
Sorensen reacted instantly, understanding that the Alpha's action meant he was about to shoot. "Sonar to control, recommend evasive action."
"Helm, left full rudder! All ahead full. Thirty degrees up angle! Sonar, activate torpedo detection frequency!"
Potemkin's torpedo room was portside amidships. Federov wheeled to the right, reversed his prop and stopped dead in the water. "Fire acoustic-homing torpedo."
Alexis hesitated, then stuck his thumb into the red button on his console. A gas turbine-propelled torpedo shot out of a tube. The projectile took off after Barracuda at forty knots, the on-board ultrasonic echo-ranging sonar probing the sea for its target. The instant the torpedo was away Federov ordered, "Stern planes, maximum down angle, all ahead one third. Take us down to one thousand three hundred meters." He must not give the Barracuda a chance to find him and shoot back. He must not think of the torpedo he had loosed. He must not think.
"Incoming! Torpedo, bearing one eight zero!"
Barracuda was racing upward at thirty degrees, trying to rise into a cooler layer of water. Springfield was counting on the torpedo's searching in a normal down-spiraling pattern. He calculated he had ten minutes before the torpedo either ran out of fuel or outpaced Barracuda and ran up her stern.
"Control to weapons, load chaff decoy."
"Weapons to control, understand load chaff decoy. Weapons to torpedo room, get the decoy in the tube."
"Torpedo room, aye aye."
When Barracuda was at four hundred feet, Springfield ordered, "Zero angle on the planes. Fire decoy."
"Decoy away."
A jet of compressed air pushed the chaff decoy out of the tube, and it promptly began to emit electronic pulses that imitated Barracuda's target-frequency sonar. The decoy began to spiral down as Barracuda continued up.
The Russian torpedo had remained at eight hundred feet, its sonar confused by the reflecting nature of the ceiling of the thermal layer. When it heard the decoy it zeroed in.
Two minutes after the decoy was fired, Sorensen and Fogarty heard the explosion.
"Goddamn," Sorensen exclaimed. "It worked. Keep your eyes on the screen, kid. There may be another one."
In the control room there was momentary relief. When the decoy destroyed the torpedo, even Springfield allowed himself a minor celebration. A moment later, however, it was replaced with a quiet fury. "Go right thirty degrees, stern planes down ten degrees. Leo, take us down to fifteen hundred feet. We've got to get this son of a bitch before he gets us. He fired first."
"One thousand three hundred meters and holding."
Potemkin was steaming at twelve knots, 4,264 feet beneath the surface of the sea. At that tremendous depth she was in the deep sound channel, and Popov's sonars were subjected to a barrage of strange noises. Ordinarily sounds in the channel were trapped by a warm thermal layer above and a very cold thermal below. The only exception was a thundering source of noise such as Potemkin herself. Potemkin with her hard-bolted machinery produced sonic signals of many different frequencies, some of which were refracted into the layer above, revealing her presence, while at the same time rendering her own sonars ineffective. Popov could hear neither Barracuda, nor the torpedo, but he did hear the unmistakable sound of an explosion.
"Captain, we got him—"
Federov looked at the screen and at Alexis, who was shaking his head. "Don't be too sure, Popov. We don't know what we hit. Go right six degrees. We'll make a wide circle."
Sorensen was standing before his console, working the down-searching sonars. "C'mon, Ivan, you shot your wad, come back and see what damage you did. C'mon…" And then to Springfield: "Sonar to control. Recommend all stop and quiet in the boat."
"Attention all hands. All stop. Quiet in the boat."
Barracuda hovered at fifteen hundred feet. Fogarty expected another torpedo, Sorensen did not. The down-searching sonars were acutely sensitive to frequencies that refracted through the various thermal layers.
A fuzzy splash of illumination appeared on one side of the screen. "There she is. Sonar to control. Contact, range six thousand yards, depth four thousand two hundred feet, bearing one one three, speed twelve knots. She's coming right at us, Captain, but she's deep."
Fogarty slammed his fist on the console. "But we can't shoot her that deep. A Mark thirty-seven will implode at twenty-five hundred feet."
Sorensen nodded. "You're right, Fogarty, but when this Alpha took a shot at us, I figure he bought himself a nuke. Our job now is to survive… and his is to see we don't."
Fogarty stared at the screen. "We wouldn't… Springfield wouldn't… Jesus, we can't—"
"Fogarty, prepare to feed the guidance system on a Mark forty-five."
Fogarty hesitated. Sorensen just stared at him, and Fogarty, numb, began punching buttons…
"Attention all hands. Battle stations, nuclear. Control to weapons, load tube six with a Mark forty-five."
In the torpedo room Lopez bit through his cigar. He stood up and crossed himself. "Johnson, cut loose a Mark forty-five. Open the door."
Four torpedomen moved along the rack and unbolted the torpedo from its mooring. A fifth opened the torpedo door. Carefully, they slid it onto the guides, and pushed it into the tube. Lopez closed the electronic locks in the proper sequence and ran the circuit tests. "Torpedo room to control," he said into his headset, "Mark forty-five loaded in tube six."
"Control to weapons, arm warhead."
Hoek was having trouble breathing. He responded in a scarcely audible whisper and pushed the coded numbers into his keyboard. "Mark forty-five warhead armed and ready."
"Flood tube."
"Flooding tube, aye."
In the sonar room Sorensen and Fogarty could only listen to the commands as they passed back and forth over the intercom.
29
The carbon dioxide scrubber on Potemkin was back in operation and the air was fresh. Federov watched the sonar console.
Barracuda was not on the screen. Federov didn't know if she was sunk or whether signal interference in the deep sound channel prevented him from hearing her. He had heard neither implosions nor a train of debris settling toward the bottom.
"Engineering, how go the stern planes?"
"This is engineering. We can move them."
"All right. Prepare for maneuvering. Slow speed. Let's be quiet."
On Sorensen's screen the Alpha decreased speed and became quieter.
"Sonar to control, range now four thousand yards and holding. He's looking for us. Depth three eight zero zero feet."
"Control to sonar, activate target-seeking sonar." And pray he comes to his senses and backs off…
Sorensen looked at Fogarty, punched the button and a wave of high-pitched sound pulsed out of Barracuda's bow in a narrow sound ray aimed directly at Potemkin.
Popov screamed in pain, his eardrums ruptured by Barracuda's target-seeking sonar. Federov rushed to the sonar console. The pulse of sound that appeared as a bright streak on the screen was like a sharp jab in his guts. Their sonar had found him.
"All ahead full. Right full rudder."
For thirty seconds Potemkin's engines pushed her through a sharp turn. "All stop," commanded Federov. "Level the planes."