I turned to make sure that McAndrew was still with me. He was, but a single glance back at the Ark was enough to tell me that I had erred on the side of optimism. The whole outer surface of the modified asteroid seethed with activity. Cranes were turning in our direction, metal manipulator jaws stretched as far as they could toward us, mobile cargo units clanked our way across the uneven surface, and the long booms of communication antennas swung out to block the path between us and the hovering Merganser.

“Straight up and out, Mac,” I cried, and fired my suit jets at maximum thrust. A rapid vertical rise, a quick controlled zig-zag to avoid a swinging antenna boom, and I was clear. The Merganser lay ahead. In half a minute I was standing in the air lock. I looked back.

McAndrew had reacted more slowly and taken longer to avoid the threshing antenna booms, but he was clear and on the final two hundred meters of his approach. Sighting beyond him, I realized that I had been optimistic yet again.

“Inside, Mac,” I shouted. “Right inside — and hang on.”

Instead of cycling the lock I did an emergency override, allowing all the air in the interior of the Merganser to puff away through the lock and into space. No problem, we had plenty of reserve and could replace it — if we survived and had the chance.

The AI inside the Ark had control over its lifeboats and space pinnaces. Four of them were lifting away from the surface and heading in our direction. They lacked space-weapons systems, but they wouldn’t need them. A direct collision at maximum acceleration would be enough to make sure that McAndrew and I did not return to the vicinity of Sol. If we survived the crash, our fates would depend on the whim of the AI.

Mac was inside, slamming shut the hatch of the life capsule. I headed for the controls. We had no space weapons, either. But we had one thing that the Ark ’s lifeboats and pinnaces did not.

I dropped, still fully suited, into the pilot’s chair and flicked the Merganser’s drive to its maximum value. The life capsule sprang into flight position and a fiery plume of plasma, hotter than dragon’s breath, spewed out on all sides of us and away behind the ship. Everything in the path of the drive exhaust melted away in a fraction of a second to its subatomic components.

The lifeboats and pinnaces exploded in eruptions of violet sparks. When the sky cleared I saw, beyond them and slightly away from the line of the drive, the floating bulk of the Cyber Ark.

I was turning the Merganser to bring its deadly drive into alignment with the Ark when I felt McAndrew’s suited hand over mine on the control stick.

“Jeanie,” he cried — louder than he ever spoke. “What are you doing?”

“It killed them,” I said. We were fighting each other for the controls, and my voice was as shaky as my hands. “Killed all of them, all two thousand people. We have to destroy it.”

“Why do you say the AI killed them?” We were face to face, and his eyes were wild.

“Look at the sequence, Mac. The first message was genuine. It had them trapped, except for the ones who tried to escape in the lifeboat. It grabbed them with the manipulator.”

“But the others — the messages.”

“I don’t think it realized that the others had a way to get a message out until our signal was received at the Ark. But then it knew, and it opened the whole interior. It killed them all. Those jerky messages were synthesized, the AI made them up just for us.”

“That’s why you can’t kill it. Don’t you see, Jeanie, it’s intelligent. Super-intelligent — it learned our language, interpreted our messages in no time at all.”

He was stronger than me, but he had poor leverage. I was winning, and the drive had almost reached the outer limb of the Ark.

“We have to kill it because it’s super-intelligent,” I said. “Super-intelligent, and insane. We have no idea what it might be able to do. There’s never been anything as dangerous to humans in the whole Universe.”

“You wouldn’t kill a baby, would you, because it was crazy?” McAndrew had changed position, and his hold on the controls was as good as mine. “Think for a minute, Jeanie. It’s morally wrong to kill any intelligent being. You’ve told me that a hundred times.”

I let go of the control stick. Not because I accepted his argument, or even because the drive on the Merganser was inadequate to sterilize the whole Ark, though it almost certainly was. I had a more practical reason. We were accelerating at a hundred and eighteen gees. In the ten seconds that we had been wrestling for the controls, the Merganser had flown almost sixty kilometers. Over such a distance our drive exhaust would inflict only minor damage on the Ark.

I took a long breath, moved away from the controls, and forced myself to begin the routine task of refilling the life capsule with air. Until that was done we could not remove our suits. We were quite safe in them, but we faced a long journey home. After a few moments McAndrew came over to help me.

Logically, he and I could and should have continued our discussion on an appropriate fate for the AI that now controlled the Cyber Ark. In fact, we said not a word to each other about the matter; not then, not when we took off our suits, not at any time during our long journey back to the Institute.

What did we discuss? We talked about everything that people do talk about — when they want to avoid talking about one particular thing.

When we finally spoke again about the AI, the Cassiopeia supernova was far past its peak. That stellar beacon had dwindled and faded, and in its place shone the wan, unspectacular remnant of a dwarf star. Paul Fogarty was back from his trip, and his findings at the solar focus were enough to provide him with a respectable amount of media coverage.

Of McAndrew’s doings regarding the supernova, the Cyber Ark, or anything else, the media said not a word. He did not call me, write me, or send me any other possible form of message.

I tell you, the man is as obstinate as a mule. So it astonished me when, as I was monitoring the loading of volatiles for a routine Ceres run, he showed up at the L-4 loading area.

He stood at the side of the deck and did absolutely nothing until finally, in exasperation, I swung over to his side.

“What, then?”

“You know what,” he said. “I’m going. Again. To the Ark. ”

“I thought you might. Who’s going with you?”

“Lots of people. Too damn many people. Computer types, military, AI specialists, psychiatrists, the works.”

I kept my mouth shut, but I think my eyebrows rose because McAndrew said, “Aye, you heard right. Psychiatrists. The leading theory is that the AI is mad.”

“I told you it was insane when we first encountered it.”

“Well, now we have others saying the same thing. Crazy, they say, because the AI has been so long in isolation, without inputs.”

“It had inputs from the humans on the Ark. And it killed the lot of them.”

“I said that. When I did, the United Space Federation just added more people. It’s going to be a whole three-ring circus out there.”

I waited. He had ended his sentence on a rising note, and I knew from experience that meant he hadn’t finished.

“So well then,” he said after a while. “What do you say, Jeanie?”

“What do I say to what?” I can be as awkward as McAndrew when I feel like it.

“Why, are you coming with us? With me. Out to the Cyber Ark.”

“If I said yes to that I’d be as crazy as the AI. I’m amazed you’d come here and ask me such a thing.”

“Ah, well, there’s more that you don’t know.” He took my hand and sat me down next to him on the edge of the lading bay. “Simonette will be leading the USF party.”