«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 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.