'What?'
'Sir, incoming torpedo depth! They've fooled us. We won't be able to intercept in time!
If we boost our units' yield, they'll just take us with them instead!'
'What the hell are you talking about?' ter Horst said. 'Have you lost your mind?'
'Don't you see, Captain?' Van Gelder said. 'The Americans, they're going for undersea nuclear Mach stems, like an airburst, only much worse! A hammer and anvil strike, two shock waves hitting us simultaneously from opposite sides, after they both redouble when each merges through the heated water with its own bottom bounce!'
Ter Horst's face went white. 'Plane up, do an EMBT blow!' Voortrekker's nose bucked and hydrazine began to roar. Then both U.S. torpedoes detonated.
'Units from tubes one and five have detonated!' Bell shouted. It would be precious seconds till Jeffrey knew what effect they'd had on Voortrekker, if any.
'Six torpedoes still incoming at high speed,' Sessions said.
'And this deep they'll all camouflet,' Jeffrey said. 'The fireballs won't break the surface.'
'Concur, sir,' Sessions said.
'It's high time to get our backsides out of here,' Jeffrey said. 'Helm, ahead flank smartly. Hard left rudder, make a knuckle, make your course two nine zero, back toward Durban.'
'Ahead flank smartly, aye,' Meltzer said. 'Hard left rudder, aye.'
'That'll take us off the track of those torpedoes,' Jeffrey said, 'and help make sure we outrun their fuel supplies.' He glanced at a depth gauge to double-check: still 12,000 feet. 'Helm, fifteen degrees down bubble smartly. Chief of the Watch, don't compensate till we reach fifteen thousand. Let us dive with negative buoyancy to pick up extra speed.'
'Fifteen degrees down bubble smartly, aye,' Meltzer said. He pushed on his control wheel — the deck nosed downward quickly.
'Transient bearing one two zero!' Sessions shouted. 'Sierra 1 is doing a main ballast blow!'
'They figured out my trick,' Jeffrey said.
'Sir?' Bell said.
'Mach stems from opposite directions dead abeam,' Jeffrey said.
'Clever lad,' Morse said. 'A nutcracker suite, and with the seawater preventing neutron warhead fratricide.'
'Sonar,' Jeffrey said, 'shut down your equipment before the enemy torpedoes start to detonate. I don't want to take a chance our gear's overloaded when the blast fronts get here through the lensing.'
'Understood,' Sessions said. 'Our own units' shock waves will reach us momentarily.' The rumbling and shaking weren't as bad as Jeffrey expected, but those detonations had been tens of kilo-yards away.
'All six enemy torpedoes still incoming, sir,' Sessions said.
'Will we be able to outrun?' Jeffrey said.
'If we stay at flank speed,' Bell said, 'and don't have a propulsion casualty, it's still touch and go, sir.'
Jeffrey picked up the mike for the 7MC. 'Maneuvering, this is the captain. Push the reactor to one hundred ten percent.' Challenger began to vibrate like a subway car. Five atomic blasts went off at progressively shorter distances from Challenger, the last of them on the nearer side of the vent field.
'Sonar,' Jeffrey said, 'reactivate your hydrophones. We need the data to evade that final fish.' 'Acknowledged,' Sessions said.
'Last incoming torpedo still narrowing the range,' Bell said. 'Twenty thousand yards now, sir.'
'What's its overtaking speed?' Jeffrey said. 'Twenty-five knots.'
'What's its depth?'
'Fifteen thousand feet.'
'Same as us,' Jeffrey said, 'and that's as deep as I want to push it.' The hydraulic-ram main compensating pumps felt asthmatic as it was.
'Captain,' Bell said, 'should we head up toward the surface where our countermeasures work?'
'They didn't work against that 212's fish at Diego Garcia,' Jeffrey said.
'There aren't any terrain features we can hide behind either,' Ilse said. 'We're over the Agulhas Basin at this point, nineteen thousand feet.'
'Uh-oh,' Jeffrey said, 'I'm not thinking. Helm, right full rudder, make your course zero zero zero.'
'Sir?' Bell said. 'That fish will cut the corner on us.'
'Yes,' Jeffrey said, 'it's a gamble. But we have to reach shallower ground.'
'What's incoming torpedo's depth now?' Jeffrey said.
'Thirteen thousand five hundred feet,' Bell said.
'Good,' Jeffrey said, 'and we're still at fifteen thousand, hugging the bottom. Looks like that fish is set to track five hundred meters above the floor but not below its crush depth, about what I suspected…Fire Control, the range?'
'Ten thousand yards,' Bell said, 'and on an interception course.'
'But we got its height-to-distance down to one to twenty,' Jeffrey said, 'so it's too close to the bottom for an effective Mach stem.'
'Concur,' Bell said. 'That was smart, sir, veering north.' 'It can still kill us the oldfashioned way very nicely,' Jeffrey said.
'If it was a high-explosives warhead,' Morse said, 'it would impact in twelve minutes. One KT's in lethal range in half that time.'
'It's obviously got passive lock on all our noise,'
Jeffrey said, 'but if we slow down any, we just help it more, and making knuckles slows us down.'
'It may be programmed to go active if it loses passive lock,' Morse said. 'I doubt then that we'd fool it with a knuckle.'
'No,' Jeffrey said, 'but it might be using a passive-only proximity fuze. If we can somehow make it think it's overtaken and it's passing us, it may blow prematurely…Helm, hard right rudder!'
'Hard right rudder, aye,' Meltzer said. The boat banked hard to starboard.
'Helm, hard left rudder!'
The boat banked hard to port.
'A pair of knuckles just might do it,' Jeffrey said, 'make our self-noise seem to fade.'
'Sir,' Sessions said, 'incoming torpedo has started pinging, ultrasonic at thirty-two kilohertz.'
'That's cute,' Jeffrey said. 'Rudder amidships.' 'Rudder amidships, aye,' Meltzer said. Challenger steadied up on zero three five true.
'Torpedo is course-correcting,' Sessions said, 'once more on a constant bearing off our stern.'
'It didn't work,' Jeffrey said. He glanced at a chronometer. 'That torpedo should have exhausted all its fuel already, even with not pinging till just now. The Axis must have an improved mod in the field. Useful Intel if we live to share it.'
'What's range to the torpedo?' Jeffrey said.
'Eight thousand yards,' Bell said.
'Sonar,' Jeffrey said, 'put your broadband on the speakers.' A harsh screaming filled the CACC, gradually getting louder, the last incoming torpedo. Mad hissing and rumbling filled the background, the warheads that had already gone off. There was a steady sharp hiss also, Challenger's own flow noise. The Axis fish's pinging was too high-pitched for the human ear.
'Sonar,' Jeffrey said, 'can you clean that up and say what else is happening out there?' Sessions tapped his keyboard and spoke to his senior chief. 'Sir, we're getting intermittent passive contact on something on the surface, assess it as Sierra 1. Best guess it's all their bilge and fire-fighting pumps.'
'Sounds like we really hurt them, Captain,' Bell said.
'But we didn't sink them,' Jeffrey said. 'Is Sierra 1 in motion?'
'Hard to be sure with all the reverb,' Sessions said, 'but we have enough slant separation over the camoufletted blast zones to drive a TMA.'
'Good,' Jeffrey said. 'Fire Control, what's the dot stack tell you?'
'Sierra 1 is stationary, Captain,' Bell said.
