«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 homeworld 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.»