by David Weber
"Fourth, the Nest's social and military actions follow patterns which, as far as we can tell, have never altered in their racial memory. Frankly, this is the most hopeful point we've discovered. We now know how their 'great visits' work and how to derail the process for quite some time."
"We do?" Gerald Hatcher scratched his nose thoughtfully. "And just how do we do that, Hector?"
"We stop this incursion," MacMahan said simply. There was a mutter of uneasy laughter, and he smiled very slightly. "No, I mean it.
"The Achuultani possess no means of interstellar FTL communication other than by ship. How they could've been around this long and not developed one is beyond me, but they haven't, which means that once a 'great visit' is launched, they don't expect to hear anything from it until it gets back."
"That's good news, anyway," Hatcher agreed.
"Yes, it is. Especially in light of some of their other limitations. Their best n-space speed is twenty-eight percent of light-speed, and they use only the lower, slower hyper bands-again, we don't understand why, but let's be grateful-which limits their best supralight speed to forty-eight lights; seven percent of what Dahak can turn out, six percent of what the Guard can turn out under Enchanach Drive, and two percent of what it can turn out in hyper. That means they take a long time to complete an incursion. Of course, unlike Enchanach Drive, there's a time dilation effect in hyper, and the lower your band, the greater the dilation, which means their voyages take a lot less time subjectively, but Brashieel's ship had already come something like fourteen thousand light-years to reach Sol. So if the incursion sent a courier home tomorrow, he'd take just under three centuries to get there. Which means, ladies and gentlemen, that if we stop them, we've got almost six hundred years before a new 'great visit' can get back here. And that we know where to go looking for them in the meantime."
A soft growl came from the assembled officers as they visualized what they could do with five or six centuries to work with.
"I'm glad to hear that, Hector," Hatcher said carefully, "but it leaves us with the little matter of three million or so ships coming at us right now."
"True," Colin said, waving MacMahan back down. "But we've learned a little-less than we'd like, but a little-about their strategic doctrine.
"First, we have a bit more time than we'd thought. The incursion is divided into three major groups: two main formations and a host of sub-formations of scouts which do most of the killing. The larger formations are mainly to back up the scout forces, each of which operates on a different axis of advance. Aside from the one which already hit us, they're unlikely to hit anything but dead planets as far as we're concerned, and a half-dozen crewed Asgerds could deal with any of them. If we can stop the main incursion, we'll have plenty of time to hunt them down and pick them off.
"The real bad news is coming at us in two parts. The first-what I think of as the 'vanguard'-is about one and a quarter million ships, advancing fairly slowly from rendezvous to rendezvous in n-space to permit scouts to send back couriers to report. We may assume one's already been dispatched from Sol, but it can't pass its message until the vanguard drops out of hyper at the rendezvous, thirty-six Achuultani light-years from Sol. Given the difference in length between our years and theirs, that's about forty-six-point-eight of our light-years. The vanguard won't reach their rendezvous for another three months; we can be there in about three and a half weeks with Dahak, and a hell of a lot less than that for the Guard in hyper.
"And take on a million ships when you get there?" Hatcher said.
"Tough odds, but I've got a mousetrap planned that should take them out. Unfortunately, it'll only work once.
"That's our problem. Even if we zap the vanguard, that still leaves what I think of as the 'main body': almost as numerous and with some really big mothers, under their supreme commander, a Great Lord Tharno.
"Now, the vanguard and main body actually keep changing relative position-they 'leapfrog' as they advance-and their rendezvous are much more tightly spaced than the scouts' are. Again, this is to allow for communication; the scouts can't pass messages laterally, and they only send one back to the closest main fleet rendezvous if they hit trouble, but the leading main formation sends couriers back to the trailing formation at each stop. If there's really bad news, the lead force calls the trailer forward to link up, but only after investigating to be sure they need help, since it plays hell with their schedules. In any case, however, at least one courier is always sent back and there's a minimum interval of about five months before the trailer can come up. With me so far?"
There were nods, and he smiled grimly.
"All right, that's our major strategic advantage: their coordination stinks. Because they use hyper drives, their ships have to stay in hyper once they go into it until they reach their destination. And because their maximum fold-space com range is barely a light-year, the rear components of their fleet always jump to the origin point of the last message from the lead formation. Even in emergencies, the follow-on echelon has to jump to to almost exactly the same point, assuming they mean to coordinate with the leaders, because with their miserable communications they can't find each other if they don't."
"Which means," Marshal Tsien said thoughtfully, "that your own ships may be able to ambush their formations as they emerge from hyper."
"Exactly, Marshal. What we hope to do is mousetrap the vanguard and wipe it out; I think we'll get away with that, but we don't know where the rendezvous point before this one is. That means we can't stop the vanguard's couriers from telling Lord Tharno about our trap, meaning that the main body will be alerted and ready when it comes out.
"So we probably will have to fight the main body. That pits seventy-eight of us against one-point-two million of them: about fifteen thousand to one."
Someone swallowed audibly, and Colin smiled that grim smile again.
"I think we can take them. We may lose a lot of ships, but we ought to be able to swing it if they pop into n-space where we expect them."
A long silence dragged out. Marshal Tsien broke it at length.
"Forgive me, but I do not see how you can do it."
"I'm not certain we can, Marshal," Colin said frankly. "I am certain that we have a chance, and that we can destroy at least half and more probably two-thirds of their force. If that's all we accomplish, we may not save Earth, but we will save Birhat and the refugees headed there. That, Marshal Tsien-" he met the huge man's eyes "-is why I'm so relieved to know we're sending one of our best people to take over Bia's defenses."
"I am honored by your confidence, Your Majesty, yet I fear you have set yourself an impossible task. You have only fifteen partially-manned warships-sixteen counting Dahak."
"But Dahak is our ace in the hole. Unlike the rest of us, he can fight all of our unmanned ships with full efficiency as long as he's in fold-space range of them."
"And if something happens to him, Your Majesty?" Tsien asked quietly.
"Then, Marshal Tsien," Colin said just as quietly, "I hope to hell you have Bia in shape by the time the incursion gets there."
CHAPTER TWENTY
"Hyper wake coming in from Sol, ma'am."
Adrienne Robbins, Lady Nergal (and it still felt weird to be a noble of an empire which had died forty-five thousand years ago), nodded and watched Herdan's holographic projection. The F5 star Terran astronomers knew as Zeta Trianguli Australis was a diamond chip five light-years astern, and the blood-red hyper trace indicator flashed almost on a line with it.
Adrienne's stupendous command floated with three other starships, yet alone and lonely. The four of them were deployed to cover almost a cubic light-year of space, and Tamman's Royal Birhat was already moving to intercept. Well, that was all right; she'd killed enough Achuultani at the Siege of Earth.
"Captain, we've got a very faint wake coming in from the east, too," her plotting officer said, and Lady Adrienne frowned. That had to be the Achuultani vanguard, and it was way ahead of schedule.
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"Emergence times?"
"Bogey One will emerge into n-space in approximately seven hours twelve minutes, ma'am; make it oh-two-twenty zulu," Fleet Commander Oliver Weinstein said. "Bogey Two's a real monster to show up at this range at all. We've got a good hundred hours before they emerge, maybe as much as five days. I'll be able to refine that in a couple of hours."
"Do that, Ollie," she said, relaxing again. The vanguard wasn't as far ahead of schedule as she'd feared, just a bigger, more visible target than anticipated.
Adrienne sighed. It had been easier to command Nergal. The battleship's computers had been no smarter than Herdan's, but they'd had nowhere near as much to do. If she'd needed to, she could be anywhere in the net through her neural feed, but Herdan was just too damned big. Even with six thousand crewmen aboard, less than five percent of her duty stations were manned. They could get by-barely-with that kind of stretch, but it was a bitch and a half. If only this ship were half as smart-hell, even a tenth as smart!-as Dahak. But they had only one Dahak, and he couldn't be committed to this job.
"Herdan," she said aloud.
"Yes, Captain?" a soft soprano replied, and Adrienne's mouth curled in a reflexive smile. It was silly for a ship named for the Empire's greatest emperor to sound like a teenaged girl, but apparently the fashion in the late Empire had been to give computers female voices, and hang the gender.
"Assume Bogey Two has scanners fifty percent more efficient than those of the scouts which attacked Earth and will emerge into n-space twelve hours from now. Compute probability Bogey Two will be able to detect detonation of Mark-Seventy gravitonic warheads at spatial and temporal loci of Bogey One's projected emergence into n-space."
"Computing." There was a brief pause. "Probability approaches zero."
"How closely?"
"Probability is one times ten to the minus thirty-second," Herdan responded. "Plus or minus two percent."
"Well, that's pretty close to zero at that, I guess," Adrienne murmured.
"Comment not understood."
"Ignore last comment," Adrienne replied, suppressing a sigh. It wasn't Herdan's fault she was an idiot, but after talking to Dahak-
"Acknowledged," Herdan said, and Lady Adrienne pressed her lips firmly together.
"Scout emergence into n-space in fourteen minutes, sir."
"Thank you, Janet," Senior Fleet Captain Tamman said, wishing he could share his tension with Amanda, and wasn't that a silly thought when he'd taken such pains to insure that he couldn't? Well, he admitted, "pains" was the wrong word, but he'd only gotten away with it because he'd found out about Colin's compulsory personnel orders assigning all pregnant Fleet personnel to the Operation Dunkirk crews a good month before Amanda had.
He thought she would forgive him someday, but he'd almost lost her once in La Paz, and then a rifle slug went right through her visor aboard Vindicator. It was only the Maker's own grace it hadn't shattered, and she'd used up most of her helmet sealant and all of her luck. He was taking no chances this time.
"Emergence in five minutes," Janet Santino said politely, and Tamman shook his head. Woolgathering, by the Maker!
"Come to Red One," he said, and his command staff settled into even more intimate communion with their consoles. His own eyes focused dreamily on the red circle delineating their target's locus of emergence, barely twenty light-seconds from their present position, while his brain concentrated on his neural feed, "seeing" directly through Birhat's superb scanners.
That courier had done a bang-up job of timing its jump, given the crudity of its computers, to hit this close to an exact rendezvous with the vanguard.
"Emergence in one minute," Santini said.
"Alpha Battery," Tamman said gently, "you are authorized to fire the moment you have a firm track."
"Emergence in thirty seconds. Fifteen. Ten. Five. Now!"
The red circle suddenly held a tiny red dot. There was a brief, eternal heartbeat of tension, and then the missiles fired.
They were sublight in order to home, but only barely so. They flashed across the display, and the dot vanished without fuss or bother, twenty kilometers of starship ripped apart by gravitonic warheads it had probably never even seen coming.
"Target," Birhat's velvety contralto purred, "destroyed."
"Thank you, Darling," someone murmured. "I hope it was good for you, too."
"Well, that's the first hurdle," Colin said as he digested Tamman's brief hypercom transmission.
"As thou sayst," Jiltanith agreed.
Colin nodded and looked around, admiring Dahak Two's spacious command deck and awesome instrumentation, and knew he would trade it all in a heartbeat for Dahak's outmoded bridge. Not that Two wasn't a fantastic fighting machine; she just wasn't Dahak. But Dahak couldn't fly this mission, and Colin refused to send his people to fight without him. Assuming anyone survived the next few months, that might be something he'd have to get used to. For now, it wasn't.
At the moment, Two was tearing through space at better than eight hundred times light-speed. Herdan was closest to the vanguard's projected emergence, and the ships which had spread out to cover the courier's probable emergence points hurried toward her. They could have made the trip in a fraction of the time in hyper, but then the vanguard might have seen them coming.
It was all right, he told himself again. Those Achuultani clunkers were so slow all twelve of the ships he'd committed to the operation would be in position long before they emerged.
"Approaching supralight shutdown, Captain," a female voice said.
"My thanks, Two," Jiltanith replied, and that was another strange thing. Colin might be an emperor and a warlord; he was also a passenger. Two could not be in better hands, but it felt odd to be riding someone else's command after all this time, even 'Tanni's.
He turned his attention to the display, and the bright green dots of his other ships blinked as Two went sublight and the stars suddenly slowed. There came Tor, the last of them, closing up nicely. Good.
"All units in position, Sire," Jiltanith said formally. "Stealth fields active."
"Thank you, Captain," Colin said with equal formality. "Now we wait."
Great Lord of Order Sorkar hated rendezvous stops, especially in the Demon Sector. Battle Comp assured him there was no real danger, and Nest Lord knew Battle Comp was always right, but there were too many horror stories about this sector. Sorkar was not supposed to know them-great lords were above the gossip of lower nestlings-but unlike most of his fellows, Sorkar had won his lordship the hard way, and he had not forgotten his origins as thoroughly as, perhaps, he ought to have.
Still, this visit had been almost boring, despite those odd reports of long-abandoned sensor arrays. Sorkar had longed for a little action more than once, for the urge to hunt was strong within any great lord, but Protectors were a commodity to be preserved for the service of the Nest, and he was too shrewd a commander to regret the tedium. Mostly.
He split his attention between his panel and the chronometers as they clicked over the last segment, and a corner of his brain double-checked the override between Battle Comp and his own panel. Battle Comp seldom took a hand directly, but it was comforting to know it could.
There! Emergence.
He watched his instruments approvingly. It was impossible to coordinate the translation between hyper space and n-space perfectly for so many units, but the time spread looked more than merely satisfactory, and the spacing was exemplary. His Protectors had learned their duties well over the-
"Alarm! Alarm! Incoming fire! Incoming fire!" a voice yelped, and Great Lord Sorkar jerked half-upright. They were light-years from the nearest star-who could be firing on them here?
But someone was, and he watched in horror as missiles of the greater thunder and something else, something beyond belief, shredded his proud starships like blazing tinder.
Nest-killers! The Demon Nest-Killers of the Demon Sector! But how? He'd studied all the previous great visits to this sector
. Never-never!-had nest-killers struck until one or more of their worlds had been cleansed! Had those mysterious sensor arrays alerted them after all? But even if they had, how could they have known to find the rendezvous? It was impossible!
Yet the missiles continued to bore in, sublight and hyper alike, and his scanners could not even see the attackers! What wizardry-?
A raucous buzzer cut through his thoughts, and his eyes flashed to Battle Comp's panel. Data codes danced as the mighty computers took over his fleet, and Great Lord Sorkar was a passenger as his ships deployed. They spread apart, thinning the nest-killers' target even as they groped blindly to find their enemy. It was a good plan, he thought, but it was costing them. Tarhish, how it was costing them! But if there truly was a nest-killer force out there, if this was not, indeed, the night-demons of frightened legend, then they would find them. Terrible as his losses were, they were as nothing against his entire force, and when Battle Comp found a tar-
