Ter Horst grabbed the binocs. "It's robotic," he said at last. He looked up at the sky and shook his fist. Van Gelder wondered if the satellite could see.
"We can't stay here, sir," Van Gelder said. "They'd gladly sacrifice an empty tanker to get one of our nuclear-powered boats."
"Fire tubes one through four!" ter Horst screamed. Then, "Port thirty rudder! Clear the bridge! Dive! Dive! Emergency deep!" The lookouts, stiff and awkward in their bulky garb, unclipped their soaking harnesses, then latched open the bridge hatch and dashed below.
Van Gelder went last. As he glanced fearfully over his shoulder, Voortrekker's conventional torpedoes hit home. Four bursting eruptions marched along the tanker's starboard side. Wreckage flew up higher than her superstructure aft. Entire sections of her waterline gaped open to the sea, and even above the driving wind Van Gelder thought he heard the ocean rushing in. Thick black smoke and dazzling flame began to spread amidships — there must have been some oil left in her auxiliary tanks and pumping systems. Machine-gun ammo cooked off vividly, red tracers jabbing into the sky. Mist and foam sprayed as Voortrekker's ballast vents first sighed, then screamed, then roared. Van Gelder stood transfixed as the sub's bow started nosing under. The tanker seemed dead in the water now, her keel beginning to sag, overstressed metal moaning and screeching. But what if she bore an atomic warhead, or maybe more than one?
Van Gelder climbed through the massive bridge hatch, made a quick inspection, and yanked it shut. He twirled the wheel to lock it as fast as he could. The Americans would wait for the tanker to be well underwater, to maximize the blast effect submerged. They'd probably use some kind of timer, or a pressure-sensitive switch. The world's biggest nuclear depth charge, Van Gelder told himself, with Voortrekker's name on it. There was a terrible drawn-out detonation and Van Gelder cringed. Voortrekker rocked but that was all. It must have been the tanker's red-hot boilers, rupturing from thermal shock as frigid seawater reached the engine rooms. But the next explosion wouldn't be from chemicals or steam, and it would be Van Gelder's last. He clung desperately to the sail trunk ladder as his boat dived hard and turned away. Van Gelder saw the lower sail trunk hatch pop open. Ter Horst looked up from below " Gunther," he said with exaggerated politeness, "would you care to come down, please?" As Van Gelder dropped into the control room, a messenger handed him a flask of genever, a high-proof gin. He gulped some gratefully, then shed his outer garments. The deck was tilted steeply and his boots squished as he walked.
Van Gelder took up his position at the conning stand next to the captain. The warmth of the genever spread throughout his body. He flexed his fingers as the circulation returned. "Helm," Van Gelder said, "report."
"Steering zero zero zero, sir," the helmsman said. Due north. "My speed is ahead flank."
"Diving Officer, report."
"Making emergency deep per captain's orders, thirty degrees down angle on the planes. Passing through six hundred fifty meters, no maximum depth specified."
"Navigator, soundings."
"Water depth fifty-eight hundred meters, sir." Van Gelder made eye contact with ter Horst.
"They fooled us, Gunther," ter Horst said. "They won't fool us again."
"Sonar," Van Gelder said, "range to the tanker?"
"Four thousand meters, sir."
"Sonar," ter Horst said, "put it on the speakers." Roaring and burbling echoed in the control room, seawater and air bubbles in vicious foregone conflict. A continuous noise like breaking glass told of steam pipes bursting endlessly. Van Gelder heard the rapid-fire pops of rivets failing, the sharp bangs of ruptured welds. The tortured screams of frames and plating punctuated the giant tanker's death, steel groaning in final torment.
"Sonar," ter Horst snapped, "target depth?"
"About two hundred meters, sir, increasing fast. She's tearing apart in the middle, still in one piece so far."
"Target range?"
"Now forty-seven hundred meters, Captain."
"I'm afraid to go any faster," ter Horst said. "I don't want to overpower the reactor … Damned Russian nuclear engineering."
"I agree, sir," Van Gelder said. "Even with the Hamburg firm's enhancements we could lose the boat."
"We still might," ter Horst said. "If that tanker's rigged with an atomic warhead, we'll know it very soon."
It was. The initial shock was so hard it made Van Gelder's vision blur. A gigantic rolling boom hammered through the hull and over the sonar speakers, strangely stereophonic. Half the control room screens imploded, ground glass flying everywhere. Crewmen's arms and legs and heads flailed wildly as Voortrekker lurched and lurched. Then the speakers all went dead but the nerve-rending thundering continued. Van Gelder's limbs and ass felt pins and needles from the impacts. He waited for the hull to crack, for the inrush of the icy crushing sea, for the sudden compression of the atmosphere that would set his clothes and skin afire.
Instead Voortrekker's stern reared up, higher and higher, lifted by the blast, throwing Van Gelder and ter Horst forward against their workstations.
"Fifty-two degrees down bubble!" the helmsman shouted. "I can't control the boat!" A soul-piercing alarm bell filled the air. "Reactor scram!" came over an intercom. "Excessive trim reactor scram!" The overhead lights dimmed immediately, switched to batteries as Voortrekker's turbogenerators wound down. Then Van Gelder heard the inevitable: "Control, Maneuvering, we've lost propulsion power!" The sub's vibrations changed in character, nastier than before.
"We're in a jam dive!" the helmsman screamed. "Cruise by wire's inoperative! Backup hydraulic system's failed!" He and the diving officer twirled their control wheels uselessly.
"Fire in the forward fan room," came over the intercom. "Flooding through the main shaft packing gland."
"Diving Officer," ter Horst said, "pump all variable ballast. Pump out the safety tanks." The intercom began to hiss and squeal, becoming unintelligible. Ter Horst tore a soundpowered phone rig from a crewman lying on the deck. The man's neck stretched like rubber and Van Gelder realized he was dead. The body slid downhill.
"Silence on the circuit!" ter Horst snapped, then, "Engineering, engage sternplane manual overrides. Can you give me back full revs on batteries?" Ter Horst listened, frowning. "Then lock the shaft and use the propulsor as a water brake. We've got to stop this dive!"
Van Gelder glanced at a depth gauge. They'd just passed 2,500 meters, rate of descent increasing fast. This far down even Voortrekker's ceramic hull compressed, reducing their buoyancy further.
"Captain," Van Gelder said, "our momentum's much too high. Recommend emergency main ballast blow while we still have the chance."
"That was a three-KT warhead out there," ter Horst said, "if not more."
"I know, sir. But we're too heavy now with the heat and gas bubbles around us." The ocean's supporting density had just dropped out from under them. "Our crush depth's coming up fast!"
"Surfaced into those tsunamis, we could turn turtle easily," ter Horst said, "spill air from the bottom of the ballast tanks and sink, even do a full three-sixty, smashing everyone and everything inside."
Van Gelder nodded. Which was the better way to die?
"Engineering," ter Horst said into the bulky mouthpiece, "status on the diveplanes? Can you shunt past the bad main motor breakers?" He paused for the response. "They need more time."
"Captain!" Van Gelder urged as he watched the depth gauge. "We've got barely sixty seconds till the hull implodes!"
"Very well," ter Horst said, sighing, "it's the lesser of two evils … Diving Officer, emergency-blow the forward main ballast group."
High-pressure air screeched like a strident harpy, forcing its way into the tanks outside the pressure hull. Enough leaked through the distribution manifold to pop Van Gelder's ears.