'His response might not be what you expect, ma'am,' Calder suggested.

'There are only two responses: fight or flight,' she explained. 'If he arrives here, my tacticians suggest he won't be able to stay long enough to cause major damage without putting Argus Station at huge risk. Most likely he will run, which will take him away from the sun and its convenient source of power. But he will not run all the way yet, because he's not ready to, and he believes he can run at any time. The orbital firing will slow him down and give you more time to commission those ships out there, and take your new weapon against him.'

Calder nodded in dubious agreement.

At the base of the dock they headed for a train where more security personnel were waiting, doubtless there simply to ensure no one slipped a bomb on the vehicle before her arrival. She stepped aboard and gazed in puzzlement at the presence of seats in this zero-gravity environment, then sat down anyway. After a moment, she copied others in pulling her seat straps across. The reason for the seats and the straps soon became evident as the train slid into motion, passing through a complicated array of seals and iris doors, out into bright sunlight and the disperse confusion of the station structure, and then accelerated.

No air to slow it down, Serene realized, as she was first pushed back into her seat, then down into it on one sweeping curve, then eventually lifting out of it against her straps, as the train slowed at a C-section station in the side of something like a steel coliseum located out in vacuum. With a sucking crump, airlocks engaged, and she was soon out into busy corridors and cage-ways, then into a control centre that seemed either in the process of being taken apart or still being put together. Serene strode over to a big outward-slanting window that overlooked something crouching within the station structure: a skyscraper of technology braced and supported by heavy beams, massive carousels at one end, massive cables feeding in all round, unmistakably a weapon.

'One of the new ones,' said Calder from behind her.

She glanced round at him. 'And the new missiles?'

'I can show you one, but they don't look particularly impressive a just a half-tonne of plain cone-shaped metal, very much in the form of an old staged-rocket crew capsule.' He pointed down towards the carousels. 'I have one ready to be loaded directly after the first test firing of an inert missile.'

'Then let the test proceed.'

Calder gestured politely to a throne-like seat facing a curving panoramic screen. Of course there would be nothing to see by looking at the railgun itself, other than perhaps some movement in the carousels. Leaving her staff to hover behind her a Elkin and the rest unsure about where to position themselves, so looking like rubes in the big city a Serene went and sat herself down.

Three scenes were visible. One was obviously from a camera positioned down on the Moon's surface, showing a plain of contorted rock and drifts of dust terminating up against a jagged range of mountains. Nearby, measuring posts had been fixed in the ground to give a sense of scale, while at the foot of the steep mountain slopes lay a scattering of lunar accommodation units and some steel-wheeled lunar rovers that had to be at least a hundred years old. The next view showed the same scene from a satellite located above the Moon a the rovers now reduced to silver specks. The third view was from even further out.

'We've got the Hubble pointing at this, too,' Calder explained, 'using a milframer camera.'

Right then, Serene couldn't remember whether that was a camera taking a million high-resolution frames a minute or a second, and she felt disinclined to ask. It basically meant that, should she want to, she could view extreme slow-motion video of the imminent events. She gestured for him to continue.

'Okay,' said Calder, his voice now issuing from a PA system. 'Power up and fire the test shot, in twenty seconds precisely.'

The movement of people in the room seemed to judder to a halt for a second, as many screen images flickered and changed. Serene shivered as a thrumming in the air ratcheted up into clear audibility: the kind of sound heard in any power station in a major sprawl.

'Firing test shot,' announced Calder unnecessarily, as the tone of the hum abruptly changed.

Nothing happened for a few seconds, during which Serene had time to feel annoyed at not asking him for more detail: such as how long it would take the missile to reach its target. Then a bright flash lit up the lunar plain and it abruptly bulged up, domed, then opened on a deep red explosion. Transferring her gaze to the video captured from orbit, Serene observed a perfectly circular wave spreading out around it. The close view briefly showed a boulder the size of a house tumbling past, before being subsumed in a wall of dust. The view from furthest out then showed a fire fading at the centre of an expanding and ever-diffusing dome of dust.

'Impressive,' Serene allowed, then glanced round at Calder. 'I presume everything was satisfactory?'

He nodded. 'There was really no reason to test the railgun a the real test comes next.'

'So, if you would lead me through what happens now?'

'The weapon is already in its power-up cycle,' Calder explained. 'Shortly, we will use the railgun at its lowest power, just as a launcher, since firing on full power would provide far too much acceleration and wreck the weapon's internal components. Once it's just clear of the station here, the weapon receives its vector and accelerates. To an outside viewer it will just seem like a railgun test firing, for the weapon will immediately start travelling at a speed equivalent to that of our previous firing, and it will then hit a target point just beyond the previous one.'

Serene smiled and returned her attention to the screens. The dust had cleared now and the old accommodation units and rovers were still in place on the other side of a brand-new crater in the face of the Moon.

'Firing weapon,' Calder announced.

This time the thrum of power remained constant, but Serene could feel the skin on her back crawl nevertheless. She waited patiently, blinked on a flash amidst those jagged mountains, then watched the whole landscape ripple. For a second, the mountain range seemed to distort through a fish-eye lens, then it erupted. The close view briefly showed the accommodation units and rovers turning into glittering fragments, before an avalanche of stone ate them up, then greyed and blinked out. The orbital view showed a blast ten times the size of the previous one, tearing an immense hole in the Moon and throwing a great plume out into space, sending rock and dust far beyond any hope of the Moon's gravity retrieving it. Serene finally gazed upon the face of the ancient satellite, now changed forever.

'Of course,' said Calder, 'the gravity effects around the warp substantially magnify the impact value.'

It had been Calder's idea to make a missile that used a vortex generator to propel it. Since it was a missile, and without the encumbrance of passengers a who would be fried by the Hawking radiation generated inside its warp bubble a it could travel faster than the speed of light; faster even than Argus Station. Such a missile, on impact, would knock out the warp bubble of that station, thus negating what Alan Saul must perceive as his big advantage: his ability to run and their inability, before going in pursuit, to know where or when he would stop and change course.

'And this one was just the Alcubierre-drive version?' she enquired.

'It was,' Calder affirmed, 'the other three are the ones that are fully armed.'

This refinement to the weapon hadn't been Calder's idea, but a suggestion from the tacticians. When one of these missiles hit the Argus warp bubble, and knocked it out, the nuclear EM warhead it also contained, which was designed to be primed by the high temperatures generated within the warp bubble, would then detonate, cooking local computers. After that, Alan Saul would no longer be running, and Argus Station would be open to assault.

The only drawback with these missiles was that their small vortex generators interfered with the vortex generators of the ships they were on, and vice versa. The ship's vortex generator could not therefore be maintained at complete readiness while they were getting a missile ready to fire, which meant a delay of up to half an hour between either drive being used. This was something the tacticians were working on, and Serene felt confident of a solution.

'So now it's time to scare the rat out of the woodpile,' she said, not entirely sure where she had heard that expression. Just then the power note in the air changed again.

'All the railguns here and on the Core stations are now firing,' explained Calder. 'Forty inert missiles. We aren't firing at full power, because if we did, they wouldn't swing round the sun towards their target.'

Their target . . . Argus Station.

Alan Saul was just about to get his wake-up call.

6.

Why Didn't He Run?

A question that will bother historians until the end of time is, 'Why didn't Alan Saul flee to somewhere far away and safe?' Surely, once he had tested his Alcubierre warp drive on his flight to Mars, then taking Argus Station to another star system, and there obtaining the materials and energy for its conversion, would have been less risky than staying in the vicinity of Earth? One explanation is that he needed additional resources for the immense journey he was about to make, but I feel that is far too simplistic. Some illumination might lie in his rescue of his sister, Var Delex. We know, from witness statements and available information, that the torture he suffered at the hands of Salem Smith had wiped his mind, so one has to ask what drove him to seek out and rescue a sister he no longer actually knew. Saul was far too logical, too far along the road to machine mentality, to be affected by any belief in fraternal love, or duty but, by his actions, it seems his unconscious still drove him. I believe his unconscious also recognized unfinished business, and a hatred of the regime created by Serene Galahad, which was little different from the one he had already tried to destroy.

Argus High up within the skeletal sphere of his ship, Saul hung in vacuum, with Var beside him. She had been insistent on his joining her for this tour of the work in progress, despite the fact that he could view it all without being physically present. She needed affirmation of her status and, quite frequently lately, it seemed that she needed reassurance, as if she was losing confidence in her own abilities.

Below them lay what remained of the original station, but with the Mars Traveller engine now being hauled down into its new position. Tech Central, which should have lain directly below him, had been dismembered and reassembled around the station core to which all inward reaching structural members now connected. It occupied the upper hemisphere of the core, the view from its windows now mostly blocked by the inner bearing endcaps of the original arcoplexes. The only really open view from there was through the gap where the Traveller engine had once been, but even that only gave a distant view of the ship's skeleton and, even now, a second new arcoplex spindle was being assembled in the way of that.

'It'll soon all be gone.' Saul pointed to the remaining pieces of the asteroid that had now been shifted out to hang alongside the new ship's core.

'It will never all be gone,' replied Var.

'Yes, I know.' He waved a hand to encompass the surrounding sphere. 'It's all out there still.'

'No, I don't mean that. Some enterprising soul took a half-tonne chunk of high nickel- and chrome-content iron and is now turning it into jewellery.'

Saul had already known this, down to the detail and dimensions of the jewellery concerned, also who was making it and when and how, and how small a dent this made in station resources. He did not mention this, however, but just let her bolster her confidence with this game of 'I know something you don't'. Meanwhile, he slid the larger part of his attention elsewhere, through the cam system and other ship's sensors, to watch as Paul and two other proctors connected up the twenty-seventh Mach-effect coil array a a device like a huge steel aphid clinging to the inner edge of a structural beam. Except for one team, all the humans had converged for Hannah and Var's planned celebration, but the proctors stopped only for their own mysterious periods of stillness. He liked seeing them work as smoothly and efficiently as his conjoined robots, but pausing occasionally as if to admire their product.

'How long?' he asked them, without actually speaking.

'With Jasper Rhine running the balancing tests, it will take fifty days,' Paul replied. 'Without him it could be done much quicker, perhaps twenty days to install and balance every one of the projected two hundred and thirty coil arrays. They must be synched with the EM component of the Rhine drive.'

The mild implication was evident there: a human was slowing down some of the work in progress. Saul ran some rapid calculations. What with many human members of the work teams now getting 'chipped', the balance was nevertheless changing. They were speeding up, becoming more adept, more robotic, but it was still the case that if he replaced every human operating aboard with a robot, the work rate would increase.

'Should I confine them all to their quarters?' Saul asked. 'Or should I exterminate them and thus free up more resources?'

'I do not respond well to rhetorical questions,' Paul replied, while smoothly connecting up power cables and propelling himself back from the array.

'Work round him,' Saul instructed. 'But allow him to feel useful.' Just as he himself was doing with his sister . . .

Saul now focused on a branching tree of his centipede robots working at the top of the sphere. The robots passed a last structural beam up that same tree to the remaining human team, who fielded it and began moving it into place. Even as he watched, the tree of robots fragmented a individual robots heading off in different directions about the sphere ready for their next tasks. Though it would have been much quicker to have just the robots fix the beam, Saul had backed Var's decision to allow this team, which included the Messina clone and Messina's old bodyguard, to accomplish this last piece of work. That seemed an extension of his initial choice to allow all the humans to survive. A moral choice? He wasn't sure he knew the meaning of the concept any more.

Saul felt it almost as a visceral clunk deep inside his torso as that same beam went into place, then as a gradual easing inside him as bolts were tightened through perfectly lined-up holes before welders glared distantly in vacuum. He now hung in a complete spherical cage, five kilometres across, in orbit about the sun, though admittedly some parts of the cage were not permanently secured since access would be needed for further materials.

'The last beam is in,' declared Var, almost belligerently.

'So a watershed has been passed?' Saul asked.

'Yes,' she affirmed. 'On the Traveller construction station, I always found that marking these occasions with some sort of celebration, no matter how minor or constrained by political oversight, increased the subsequent work rates.'

'Certainly,' Saul replied, noting to himself how robots did not need such motivation. However, the bulk of his attention remained focused elsewhere, because new data were coming in.

Serene Galahad's comlifers had blocked his access to all of Earth's satellites and computer systems, also the solar observation satellites, but they had not extended their range far, merely cut off all other installations beyond Earth's orbit from any contact with Earth. The Martian satellites were available to Saul, but they were far away and transmission delays were long. Still, just a few million kilometres out, an old satellite orbited the sun in a parallel path to the Earth's. It had been overlooked because it remained mostly powered down until it detected comets or asteroids arriving in-system that might be a danger to Earth. Saul had sent a relay out from behind the sun, made a connection through it to that elderly satellite, and turned its radio and optical telescope array so as to now watch the home world.

'Railgun,' he remarked, his tone belying his sudden qualms. Galahad was working fast.

'What?' asked Var.

'About twenty minutes ago, Galahad fired a very powerful railgun at the Moon.' So saying, Saul instituted an immediate check on Argus's weapons. Two railguns were operational but the plasma cannon that the Saberhagen twins were building was still far from completion. Perhaps his allocation of resources had been in error? Yes, Earth was a danger that could not be ignored a and in an instant he began to divert resources. The Saberhagens would shortly be receiving the components they were waiting for.

'Second firing,' he now said, appalled at the destructive power of what he had just witnessed. 'They must have solved the component distortion problem, because that looked like a railgun-fired nuclear weapon.'

'Seems a bit advanced for them,' said Var sniffily.

'Any more advanced than building vortex . . .' Saul felt a sudden surge of both annoyance and frustration, immediately followed by the realization that he had become arrogant. Even as he sent the orders for the smelting plants to close down immediately and retract, he considered how, if he had only been watching still from Mars, they would have been in serious trouble, because he was now witnessing a launch of railgun missiles around the sun directly towards their position. Thankfully, so as to obtain the correct orbital vector, they were travelling slowly, but he was well aware that if he hadn't been watching, he would have had to sacrifice both smelting plants just to save his ship.

'This is a problem?' Var enquired.

'Yes, and I've just given orders for everyone to prepare for a shift in precisely one hour,' he replied. 'It seems Galahad wants to let us know she hasn't forgotten us. Forty railgun missiles are now heading round the sun towards us.'

Using the impeller on the wrist of his suit, Saul rapidly sent himself down towards the ship's core, with Var in quick pursuit.

'We need the solar energy,' she protested.

'We're not moving far,' he replied.

To avoid these approaching missiles, they only had to move a small distance relative to the sun, which could have been achieved with the steering thrusters or even the Mach-effect drive, were it operational. However, there was too much equipment, not to mention the remainder of the asteroid and the Traveller engine, unsecured inside the station. They must move without inertia, therefore the Rhine drive was required so Saul checked its status, as he had been checking it so often. Major changes to the station's structure, including the heavy armour being put in place in the station ring, had caused distortions in the vortex generator that had been necessary to straighten out. It was good, as he knew from the last time he checked it, just a few minutes before.

Approaching the surface of the ship's core, he slowed himself with his impeller just enough so he could absorb the remaining impact by bending his knees and have his gecko soles still remain in place. Var landed shortly after him and he was pleased, for her, to see that she had landed as perfectly as himself. He strode towards the nearest airlock, heaved open the door, pushed himself down inside, and waited until his sister crammed in beside him. The airlock gave them access to a corridor leading to the Tech Central control centre, which internally had been left much as before. Saul removed his VC suit helmet and clipped it to his belt.

'Humans in space really need to start thinking less two-dimensionally,' Var commented, as she followed him.

'To do that,' Saul replied, 'humans either have to change, or have been raised in a zero-g environment.'

'Well, even that's started now.'

Saul nodded in grave agreement. Those being 'chipped' provided an example of the former . . . but he didn't know how to react to the news that some station personnel were getting pregnant, and that thus far eight in all had refused termination. This could be taken as meaning they were starting to feel safe, but this urge to procreate was more probably a response to the constant danger: a biological imperative and a hedge against the future.

He entered Tech Central to find that Hannah, the Saberhagens, Rhine, Le Roque and even Langstrom were present. This event was something cooked up by Hannah and Var between them, Hannah having brought two bottles of fizzy wine, which was brewed on the station, and a collection of the special glasses required for drinking such a beverage in zero gravity. This gathering was so that the main players aboard the station could celebrate the fixing of the last structural beam. Var had also allowed all the work crews a shift off to celebrate similarly a a humanizing event a and a large number of them were waiting in the Arboretum for the return of Ghort's team, before the party began. Currently, however, Le Roque and Brigitta were speaking into their fones, and Langstrom and Rhine were working consoles, while Hannah stood on her own beside a medical gurney wheeled in specially to carry the drink and glasses. The rest of the station's personnel, meanwhile, were receiving the news that the station would shortly be on the move, and the party atmosphere was fast dissipating.

'Too human for you?' Hannah snapped at Saul.

'No, it seems Galahad wants to spoil your party,' he replied tightly, then shot at Le Roque, 'You have tracking on them?'

'I do, and they're up on all screens and accessible to all personnel,' the station's technical director replied. 'Every damned one of them is on target and we have to move.'

Saul turned back to Hannah, who had now been joined by Var. 'Railgun missiles heading straight for us. I feel they are an important reminder to us all.'

'Yes, I know,' she replied, suddenly looking tired.

Rhine was working his drive, Saul deliberately not interfering but keeping a watch on him from the inside of the computer system. The warp bubble should be near enough spherical despite the remaining mass of the asteroid, and the shift would be a short one, but still the margins for error were tight. Saul did not want to risk losing any of the newly constructed parts of the station. He walked over to join Hannah and Var.

'In fact, this celebration has made things easy for us,' he offered. 'All but one of the human teams have locked down their work and are not presently anywhere that might be dangerous, while the team that fixed that last beam is on its way in.' Even as he said this, his mind was ranging throughout the station, constantly checking. If the station hit anything large enough to knock out the warp, then they might experience a momentum change; however, there were impellers mounted on the biggest unsecured objects a the Mars Traveller engine and the asteroid chunk a and any drift could be corrected.

'Oh, goody,' Hannah replied.

Var popped the cap off of one of the bottles. 'They didn't need to give us a reminder. The images I've seen of those three ships they're building tell the whole story.' She used a small manual pump on the base of the bottle to squirt a stream of the wine into one of the capped glasses, then paused in bringing the glass straw up to her mouth. Everyone in the control room was staring at her. 'What? It seems a shame to let it get warm.' She sipped.

The shift was imminent and they could all feel it: a slightly different sensation now, as if the new surrounding superstructure was somehow distorting whatever it was that affected them. Saul nodded towards the glasses on the gurney. 'Pour them all.'

Var raised an eyebrow and did as instructed. She was already on the third glass when the drive engaged. The light of the sun dropped rapidly through the spectrum, and the moment of their shift was marked by a flash of intense red through the windows. Then the sun was back, glaring on the structures visible outside.

'Just a few thousand kilometres,' said Rhine.

Saul focused through that warning satellite on the stations ranged about Earth. By his calculation, it was possible that the enemy had tens of thousands of railgun missiles available. If it had been Galahad's intention just to send them a reminder, then fine; the smelting plants could be extended and they could simply get back to work here. However, if the dictator of Earth was intent on driving them away from their power supply, that was a different matter. Saul did not want to spend the next weeks, if not months, dodging pot-shots from Earth, nor did he like the idea of the work here going on hold during that period. Galahad could commission her ships within that period and he would be forced to run out-system before having achieved what he wanted here a without having made the necessary preparations for the immense journey across interstellar void.

'Drink your drinks,' he instructed, taking a sip of the wine himself while wondering how alcohol might affect or impair the distributed functioning of his mind.

They all gathered round to accept their glasses in turn. Saul moved away to gaze out through the windows of Tech Central. He decided against ordering the smelting plants to be extended again just yet. Calculating signal delays, he reckoned on twenty-three minutes before Galahad learned that they had moved, then a further twenty-eight minutes before he learned if she had devised an immediate response to that. Meanwhile he watched the workers coming in, the proctors installing further elements of the Mach-effect drive, and simultaneously absorbed detail and tweaked and changed his plans to greater efficiency.

'She can't touch us,' said Langstrom with relish.

Saul turned to him, a hollow feeling in his stomach. 'On the contrary,' he replied, now seeing a second launching of missiles from the vicinity of Earth. This launching was early, before Galahad could know they had moved, a wide spread to incorporate where some tactical team of hers had calculated he might move his ship. None of them was on target, but Galahad's message had been delivered. Walking past Langstrom to join the rest, he announced, 'We're shifting again.' And immediately began inputting new coordinates, factoring in known solar-system debris and deciding on two further shifts to take them to their first destination.

There was time yet, so he would allow all solar energy collection to continue for a while yet. He studied the disappointed expressions around him.

'We would have had to have moved shortly, anyway,' he stated, his voice taking on an echo as it repeated through the PA system, 'since we are running out of materials.'

They then watched him attentively, aware that he had something more to say. Via cams throughout the station, he saw people turning to public screens now displaying his face.

'A second launching of railgun missiles is heading on its way towards us,' he continued, 'and it is a simple fact, with the resources Earth commands and its supply lines established, that they could keep up this rate of fire indefinitely. We are therefore going to shift away from the sun.'

'We need energy,' Var protested pedantically, 'and you're taking us away from it.'