‘Jorge,’ she datavised. ‘I’ve lost him.’

  ‘Then get after him.’

  Marcus’s collar sensors showed him a spray of incendiary droplets fizzing out of the wall barely a metre behind him. The multipurpose tool must be some kind of laser pistol. ‘Katherine,’ he datavised. ‘Retract Lady Mac’s airlock tube. Now. Close the outer hatch and codelock it. They are not to come on board.’

  ‘Acknowledged. How do we get you back?’

  ‘Yes, Captain,’ Jorge datavised. ‘Do tell.’

  Marcus dodged down a junction. ‘Have Wai stand by. When I need her, I’ll need her fast.’

  ‘You think you can cut your way out of the shell, Captain? You have a fission blade, and that shell is held together by a molecular bonding generator.’

  ‘You touch him, shithead, and we’ll fry that fucking wreck,’ Karl datavised. ‘Lady Mac’s got maser cannons.’

  ‘But do you have the command codes, I wonder. Captain?’

  ‘Communication silence,’ Marcus ordered. ‘When I want you, I’ll call.’

  *

  Jorge’s boosted muscles allowed him to ascend stairwell three at a speed which Antonio could never match. He was soon left struggling along behind. The airlock was the tactical high ground, once he had secured that, Jorge knew he’d won. As he climbed his hands moved automatically, assembling the weapon from various innocuous-looking pieces of equipment he was carrying on his utility belt.

  ‘Victoria?’ he datavised. ‘Have you got him?’

  ‘No. He broke my shoulder, the bastard. I’ve lost him.’

  ‘Go to the nearest stairwell, I expect that’s what he’s done. Antonio, go back and meet her. Then start searching for him.’

  ‘Is that a joke?’ Antonio asked. ‘He could be anywhere.’

  ‘No, he’s not. He has to come up. Up is where the airlock is.’

  ‘Yes, but—’

  ‘Don’t argue. And when you find him, don’t kill him. We have to have him alive. He’s our ticket out. Our only ticket, understand?’

  ‘Yes, Jorge.’

  When he reached the airlock, Jorge closed the inner hatch and cycled the chamber. The outer hatch dilated to show him the Lady Macbeth’s fuselage fifteen metres away. Her airlock tube had retracted, and the fuselage shield was in place.

  ‘This is a no-win stand-off,’ he datavised. ‘Captain, please come up to the airlock. You have to deal with me, you have no choice. The three of us will leave our weapons over here, and then we can all go back on board together. And when we return to a port none of us will mention this unfortunate incident again. That is reasonable, surely?’

  *

  Schutz had just reached the bridge when they received Jorge’s datavise.

  ‘Damn! He’s disconnected our cable from the communication block,’ Karl said. ‘We can’t call the Captain now even if we wanted to.’

  Schutz rolled in midair above his acceleration couch and landed gently on the cushioning. Restraint webbing slithered over him.

  ‘What the hell do we do now?’ Roman asked. ‘Without the command codes we’re bloody helpless.’

  ‘It wouldn’t take that long for us to break open the weapons cabinet,’ Schutz said. ‘They haven’t got the Captain. We can go over there and hunt them down with the carbines.’

  ‘I can’t sanction that,’ Katherine said. ‘God knows what sort of weapons they have.’

  ‘Sanction it? We put it to the vote.’

  ‘It’s my duty watch. Nobody votes on anything. The last order the Captain gave us was to wait. We wait.’ She datavised the flight computer for a channel to the MSV. ‘Wai, status, please?’

  ‘Powering up. I’ll be ready for a flight in two minutes.’

  ‘Thank you.’

  ‘We have to do something!’ Karl said.

  ‘For a start you can calm down,’ Katherine told him. ‘We’re not going to help Marcus by doing anything rash. He obviously had something in mind when he told Wai to get ready.’

  The hatchway to the Captain’s cabin slid open. Marcus air-swam out and grinned round at their stupefied expressions. ‘Actually, I didn’t have any idea what to do when I said that. I was stalling.’

  ‘How the fuck did you get back on board?’ Roman yelped.

  Marcus looked at Katherine and gave her a lopsided smile. ‘By being right, I’m afraid. The dish is a distress beacon.’

  ‘So what?’ she whispered numbly.

  He drifted over to his acceleration couch and activated the webbing. ‘It means the wormhole doesn’t go back to the xenoc homeworld.’

  ‘You found out how to use it!’ Karl exclaimed. ‘You opened its other end inside the Lady Mac.’

  ‘No. There is no other end. Yes, they built it as part of their survival operation. It was their escape route, you were right about that. But it doesn’t go somewhere; it goes somewhen.’

  *

  Instinct had brought Marcus to the portal chamber. It was as good as any other part of the ship. Besides, the xenocs had escaped their predicament from here. In a remote part of his mind he assumed that winding up on their home-world was preferable to capture here by Jorge. It wasn’t the kind of choice he wanted to make.

  He walked slowly round the portal. The pale violet emanation in the air around it remained constant, hazing the dull surface from perfect observation. That and a faint hum were the only evidence of the massive quantity of power it consumed. Its eternal stability a mocking enigma.

  Despite all the logic of argument he knew Katherine was wrong. Why build the dish if you had this ability? And why keep it operational?

  That factor must have been important to them. It had been built in the centre of the ship, and built to last. They’d even reconfigured the wreck to ensure it lasted. Fine, they needed reliability, and they were masters of material science. But a one-off piece of emergency equipment lasting thirteen thousand years? There must be a reason, and the only logical one was that they knew they would need it to remain functional so they could come back one day.

  The SII suit prevented him from smiling as realization dawned. But it did reveal a shiver ripple along his limbs as the cold wonder of the knowledge struck home.

  *

  On the Lady Mac’s bridge, Marcus said: ‘We originally assumed that the xenocs would just go into zero-tau and wait for a rescue ship; because that’s what we would do. But their technology allows them to take a much different approach to engineering problems.’

  ‘The wormhole leads into the future,’ Roman said in astonishment.

  ‘Almost. It doesn’t lead anywhere but back to itself, so the length inside it represents time not space. As long as the portal exists you can travel through it. The xenocs went in just after they built the dish and came out again when their rescue ship arrived. That’s why they built the portal to survive so long, it had to carry them through a great deal of time.’

  ‘How does that help you get here?’ Katherine asked. ‘You’re trapped over in the xenoc wreckage right now, not in the past.’

  ‘The wormhole exists as long as the portal does. It’s an open tube to every second of that entire period of existence, you’re not restricted which way you travel through it.’

  *

  In the portal chamber Marcus approached one of the curving black buttress legs. The artificial gravity was off directly underneath the doughnut so the xenocs could rise into it. But they had been intent on travelling into the future.

  He started to climb the buttress. The first section was the steepest; he had to clamp his hands behind it, and haul himself up. Not easy in that gravity field. It gradually curved over, flattening out at the top, leaving him standing above the doughnut. He balanced there precariously, very aware of the potentially lethal fall down onto the floor.

  The doughnut didn’t look any different from this position, a glowing ring surrounding the grey pressure membrane. Marcus put one foot over the edge of the exotic matter, and jumped.

  He fell clean
through the pressure membrane. There was no gravity field in the wormhole, although every movement suddenly became very sluggish. To his waving limbs it felt as if he was immersed in some kind of fluid, though his sensor block reported a perfect vacuum.

  The wormhole wall was insubstantial, difficult to see in the meagre backscatter of light from the pressure membrane. Five narrow lines of yellow light materialized, spaced equidistantly around the wall. They stretched from the rim of the pressure membrane up to a vanishing point some indefinable distance away.

  Nothing else happened. Marcus drifted until he reached the wall, which his hand adhered to as though the entire surface was one giant stikpad. He crawled his way back to the pressure membrane. When he stuck his hand through, there was no resistance. He pushed his head out.

  There was no visible difference to the chamber outside. He datavised his communication block to search for a signal. It told him there was only the band from one of the relay blocks in the stairwells. No time had passed.

  He withdrew back into the wormhole. Surely the xenocs hadn’t expected to crawl along the entire length? In any case, the other end would be thirteen thousand years ago. Marcus retrieved the xenoc activation code from his neural nanonics, and datavised it.

  The lines of light turned blue.

  He quickly datavised the deactivation code, and the lines reverted to yellow. This time when he emerged out into the portal chamber there was no signal at all.

  *

  ‘That was ten hours ago,’ Marcus told his crew. ‘I climbed out and walked back to the ship. I passed you on the way, Karl.’

  ‘Holy shit,’ Roman muttered. ‘A time machine.’

  ‘How long was the wormhole active for?’ Katherine asked.

  ‘A couple of seconds, that’s all.’

  ‘Ten hours in two seconds.’ She paused, loading sums into her neural nanonics. ‘That’s a year in thirty minutes. Actually, that’s not so fast. Not if they were intending to travel a couple of thousand years into the future.’

  ‘You’re complaining about it?’ Roman asked.

  ‘Maybe it speeds up the further you go through it,’ Schutz suggested. ‘Or more likely we need the correct access codes to vary its speed.’

  ‘Whatever,’ Marcus said. He datavised the flight computer and blew the tether bolts which were holding Lady Mac to the wreckage. ‘I want flight-readiness status, people, please.’

  ‘What about Jorge and the others?’ Karl asked.

  ‘They only come back on board under our terms,’ Marcus said. ‘No weapons, and they go straight into zero-tau. We can hand them over to Tranquillity’s serjeants as soon as we get home.’ Purple course vectors were rising into his mind. He fired the manoeuvring thrusters, easing Lady Mac clear of the xenoc shell.

  *

  Jorge saw the sparkle of bright dust as the explosive bolts fired. He scanned his sensor collar round until he found the tethers, narrow grey serpents flexing against the speckled backdrop of drab orange particles. It didn’t bother him unduly. Then the small thrusters ringing the starship’s equator fired, pouring out translucent amber plumes of gas.

  ‘Katherine, what do you think you’re doing?’ he datavised.

  ‘Following my orders,’ Marcus replied. ‘She’s helping to prep the ship for a jump. Is that a problem for you?’

  Jorge watched the starship receding, an absurdly stately movement for an artifact that big. His respirator tube seemed to have stopped supplying fresh oxygen, paralysing every muscle. ‘Calvert. How?’ he managed to datavise.

  ‘I might tell you some time. Right now, there are a lot of conditions you have to agree to before I allow you back on board.’

  Pure fury at being so completely outmanoeuvred by Calvert made him reach automatically for his weapon. ‘You will come back now,’ he datavised.

  ‘You’re not in any position to dictate terms.’

  Lady Macbeth was a good two hundred metres away. Jorge lined the stubby barrel up on the rear of the starship. A green targeting grid flipped up over the image, and he zeroed on the nozzle of a fusion-drive tube. He datavised the X-ray laser to fire. Pale white vapour spewed out of the nozzle.

  *

  ‘Depressurization in fusion drive three,’ Roman shouted. ‘The lower deflector coil casing is breeched. He shot us, Marcus, Jesus Christ, he shot us with an X-ray.’

  ‘What the hell kind of weapon has he got back there?’ Karl demanded.

  ‘Whatever it is, he can’t have the power capacity for many more shots,’ Schutz said.

  ‘Give me fire control for the maser cannons,’ Roman said. ‘I’ll blast the little shit.’

  ‘Marcus!’ Katherine cried. ‘He just hit a patterning node. Stop him.’

  Neuroiconic displays zipped through Marcus’s mind. Ship’s systems coming on-line as they shifted over to full operational status, each with its own schematic. He knew just about every performance parameter by heart. Combat-sensor clusters were already sliding out of their recesses. Maser cannons powering up. It would be another seven seconds before they could be aimed and fired.

  There was one system with a faster response time.

  ‘Hang on,’ he yelled.

  Designed for combat avoidance manoeuvres, the fusion-drive tubes exploded into life two seconds after he triggered their ignition sequence. Twin spears of solar-bright plasma transfixed the xenoc shell, burning through deck after deck. They didn’t even strike anywhere near the airlock which Jorge was cloistered in. They didn’t have to. At that range, their infrared emission alone was enough to break down his SII suit’s integrity.

  Superenergized ions hammered into the wreck, smashing the internal structure apart, heating the atmosphere to an intolerable pressure. Xenoc machinery detonated in tremendous energy bursts all through the structure, the units expending themselves in spherical clouds of solid light which clashed and merged into a single wavefront of destruction. The giant rock particle lurched wildly from the explosion. Drenched in a cascade of hard radiation and subatomic particles, the unicorn tower at the centre of the dish snapped off at its base to tumble away into the darkness.

  Then the process seemed to reverse. The spume of light blossoming from the cliff curved in on itself, growing in brightness as it was compressed back to its point of origin.

  Lady Mac’s crew were straining under the five-gee acceleration of the starship’s flight. The inertial-guidance systems started to flash priority warnings into Marcus’s neural nanonics.

  ‘We’re going back,’ he datavised. Five gees made talking too difficult. ‘Jesus, five gees and it’s still pulling us in.’ The external sensor suite showed him the contracting fireball, its luminosity surging towards violet. Large sections of the cliff were flaking free and plummeting into the conflagration. Black lightning cracks were splitting open right across the rock.

  He ordered the flight computer to power up the nodes and retract the last sensor clusters.

  ‘Marcus, we can’t jump,’ Katherine datavised, her face pummelled into frantic creases by the acceleration. ‘It’s a gravitonic emission. Don’t.’

  ‘Have some faith in the old girl.’ He initiated the jump.

  An event horizon eclipsed the Lady Macbeth’s fuselage.

  Behind her, the wormhole at the heart of the newborn micro-star gradually collapsed, pulling in its gravitational field as it went. Soon there was nothing left but an expanding cloud of dark snowdust embers.

  *

  They were three jumps away from Tranquillity when Katherine ventured into Marcus’s cabin. Lady Mac was accelerating at a tenth of a gee towards her next jump coordinate, holding him lightly in one of the large black-foam sculpture chairs. It was the first time she’d ever really noticed his age.

  ‘I came to say sorry,’ she said. ‘I shouldn’t have doubted.’

  He waved limply. ‘Lady Mac was built for combat, her nodes are powerful enough to jump us out of some gravitonic field distortions. Not that I had a lot of choice. Still, we only reduc
ed three nodes to slag, plus the one dear old Jorge damaged.’

  ‘She’s a hell of ship, and you’re the perfect captain for her. I’ll keep flying with you, Marcus.’

  ‘Thanks. But I’m not sure what I’m going to do after we dock. Replacing three nodes will cost a fortune. I’ll be in debt to the banks again.’

  She pointed at the row of transparent bubbles which all held identical antique electronic circuit boards. ‘You can always sell some more Apollo command module guidance computers.’

  ‘I think that scam’s just about run its course. Don’t worry, when we get back to Tranquillity I know a captain who’ll buy them from me. At least that way I’ll be able to settle the flight pay I owe all of you.’

  ‘For Heaven’s sake, Marcus, the whole astronautics industry is in debt to the banks. I swear I never could understand the economics behind starflight.’

  He closed his eyes, a wry smile quirking his lips. ‘We very nearly solved human economics for good, didn’t we?’

  ‘Yeah. Very nearly.’

  ‘The wormhole would have let me change the past. Their technology was going to change the future. We could have rebuilt our entire history.’

  ‘I don’t think that’s a very good idea. What about the grandfather paradox for a start? How come you didn’t warn us about Jorge as soon as you emerged from the wormhole?’

  ‘Scared, I guess. I don’t know nearly enough about quantum temporal displacement theory to start risking paradoxes. I’m not even sure I’m the Marcus Calvert that brought this particular Lady Macbeth to the xenoc wreck. Suppose you really can’t travel between times, only parallel realities? That would mean I didn’t escape into the past, I just shifted sideways.’

  ‘You look and sound pretty familiar to me.’

  ‘So do you. But is my crew still stuck back at their version of the wreck waiting for me to deal with Jorge?’