“We have made a beginning,” went on Yifter quietly. “Just a beginning. Last time we were less successful than I had hoped. We had a breakdown in the distribution system for the drugs. I managed to eliminate the responsible individuals, but it was too late to correct the problem. Next time, God willing, it will be different.”

He rose to his feet, white hair shining like silver, face beatific. “Good night, Captain. Good night, Professor McAndrew. Sleep well.”

After he had left, McAndrew and I sat and looked at each other for a long time. Finally, he broke the spell.

“Now we know, Jeanie. We should have guessed it from the beginning. Mad as a hatter. The man’s a raving lunatic. Completely psychotic.”

That said most of it. McAndrew had used up all the good phrases. I nodded.

“But did you feel the strength in him?” went on McAndrew. “Like a big magnet.”

I was glad that the penal colony was so far from Earth, and the avenues of communication so well-guarded. “Next time… it will be different.” Our two-month trip suddenly seemed to have doubled in length.

After that single, chilling moment, there were no more shocks for some time. Our regular meal-time conversations continued, and on several occasions McAndrew voiced views on pacifism and the protection of human life. Each time, I waited for Yifter’s reply, expecting the worst. He never actually agreed with Mac — but he did not come out with any statement that resembled his comments of the first ship-evening.

We soon settled into the ship-board routine. McAndrew spent less and less time in the Control Stage, and more in Section Seven. On this trip, he had brought a new set of equipment for his experiments, and I was very curious to know what he was up to. He wouldn’t tell. I had only one clue. Section Seven was drawing enormous energy from the other kernels in the rest of the Assembly. That energy could only be going to one place — into the kernel in Section Seven. I suspected that McAndrew must be spinning it up, making it closer to an “extreme” kernel, a Kerr-Newman black hole where the rotation energy matches the mass energy. I knew that couldn’t be the whole story. McAndrew had spun up the kernels before, and he had told me that there was no direct way of getting a really extreme kernel — that would take an infinite amount of energy. This time, he was doing something different. He insisted that Section Seven had to be off-limits to everybody.

I couldn’t get him to talk about it. There would be a couple of seconds of silence from him, then he would stand there, cracking his finger joints as though he were snapping out a coded message to me. He could be a real sphinx when he chose.

Two weeks from Earth, we were drawing clear of the main Asteroid Belt. I had just about concluded that my worries for the trip were over when the radar reported another ship, closing slowly with us from astern. Its spectral signature identified it as the Lesotho, a cruise liner that usually ran trajectories in the Inner System. It was broadcasting a Mayday, and flying free under zero drive power.

I thought about it for a moment, then posted Emergency Stations throughout the Assembly. The computed trajectory showed that we would match velocities at a separation of three kilometers. That was incredibly close, far too close to be accidental. After closest approach, we would pull away again — we were still under power, accelerating outward, and would leave the Lesotho behind.

I was still watching the displays, trying to decide whether or not to take the next step — shutting off the drives — when Bryson appeared, with Yifter just behind him.

“Captain Roker,” he said, in his usual imperious manner. “That’s an Earth ship there, giving you a distress signal. Why aren’t you doing anything about it?”

“If we wait just a few minutes,” I said. “We’ll be within spitting distance of her. I see no point in rushing in, until we’ve had a good look at her. I can’t think what an Inner System ship would be doing, free-falling out here beyond the Belt.”

That didn’t cool him. “Can’t you recognize an emergency when you see one?” he said. “If you won’t do something productive with your people, I’ll do something with mine.”

I wondered what he wanted me to do, but he walked away without saying anything more, down the stairs that led to the rear communication area of the Control Stage. I turned back to the displays. The Lesotho was closing on us steadily, and now I could see that her locks were open. I cut our propulsion to zero and switched off all the drives. The other ship was tumbling slowly, drive lifeless and aft nacelles crumpled. Even from this distance, I could see that she would need extensive repairs before she could function again.

I was beginning to think that I had been over-cautious when two things happened. Yifter’s guards, who had been housed behind the Control Stage in Section Two, began to float into view on the viewing screen that pointed towards the Lesotho. They were all in space armor and heavily weaponed. At the same time two suited figures appeared in the open forward lock of the other vessel. I cut in the suit frequencies on our main board.

“—shield failure,” said the receiver. “Twenty-seven survivors, and bad injuries. We must have painkillers, medical help, water, food, oxygen and power-packs.”

With that, one group of our guards outside began to move towards the two suited figures in the Lesotho ’s lock, while the remainder stayed close to the Assembly, looking across at the other ship. Subconsciously, I noted the number of our guards in each party, then gave them my full attention and did a rapid re-count. Twenty-five. All our guards. I swore and cut in the transmitter.

“Sergeant, get half of those men back inside the Assembly shields. This is Captain Roker. I’m over-riding any other orders you may have received. Get the nearer party—”

I was interrupted. The display screen flashed blue-white, then over-loaded. The whole Control Stage rang like a great bell, as something slapped hard on the outer shield. I knew what it was: a huge pulse of hard radiation and highly energetic particles, smashing into us in a fraction of a microsecond.

Yifter had been floating within a couple of meters of me, watching the screens. He put his hand to the wall to orient himself as the Control Stage vibrated violently. “What was that?”

“Thermonuclear explosion,” I said shortly. “Hundred megaton plus. On the Lesotho.”

All the screens on that side were dead. I activated the standby system. The Lesotho had vanished. The guards had vanished with it, vaporized instantly. All the cables linking the parts of the Assembly, all the scanners and sensors that were not protected behind the shields, were gone. The Sections themselves were intact, but their coupling fields would have to be completely recalibrated. We wouldn’t be arriving at Titan on schedule.

I looked again at Yifter. His face was now calm and thoughtful. He seemed to be waiting, listening expectantly. For what? If the Lesotho had been a suicide mission, manned by volunteers who sought revenge on Yifter, they hadn’t had a chance. They couldn’t destroy the Assembly, or get at Yifter. If revenge were not the purpose, what was the purpose?

I ran through in my mind the events of the past hour. With the drives switched off in the Assembly, we had an unprotected blind spot, dead astern. We had been putting all our attention on the Lesotho. Now, with the guards all dead, the Control Stage was undefended.

It was quicker to go aft and take a look than to call Bryson or McAndrew and ask them what they could see from the rear viewing screens of the Control Stage. Leaving Yifter, I dived head-first down the stairway — a risky maneuver if there were any chance that the drive might come back on, but I was sure it couldn’t.