He leaped at me, dragging me to the floor. The knife was already out of his shoulder, was slicing toward my throat. I stopped it, and wrestled him for control of it. He was strong and young-- I was younger and a good deal stronger. Also, he was quite unskilled in the use of the knife. He probably had never had to use it in a situation where his enemy could see it coming.

I had him pinned to the floor and was demanding that he tell me where he was from before I killed him when I heard a sound from the door. I looked and saw no one-- but the door was still swinging open. If the illuders could do all I had already seen them do, they could probably make me think I saw no one: I was sure someone else was in the room. Interrogation would be impossible with an audience of illuders, and now they were warned. I had had one chance, not a very good one, to find out where they were from. Now I had lost it.

I pushed into quicktime and arose from where my erstwhile opponent lay on the ground. Not one but three illuders were already heading toward where I had been, knives ready. It was pointless, but I took the knives out of their hands and brought them with me into the throne room, where the old lady who was pretending to be Percy Barton sat on the throne looking bored. I placed the knives in her lap, blades pointing toward her, and then walked out of the palace. The message would be clear-- she could have been killed. But it was only a message, only a could-have-been, and I didn't know what to do next.

Kill them all? Pointless, utterly wasted if I didn't know where they were from. They would only be replaced by fellow illuders, and the plot would hardly be thwarted, only mildly delayed. As it was I did have some time to plan my next move, in quicktime, at least-- it would be a week before riders could get from Gill to another capital of any size, and with a week in quicktime I could accomplish a lot.

I left the palace. They would hardly leave records lying around saying, "The impostors in this palace come from the following Family." I would have to use reason alone to determine their homeland. And when it came to reasoning, I had learned to respect Lord Barton.

"You weren't gone long enough," he said after I sent the girl out of the room. "You impose on our friendship."

"I need your advice."

"And I need solitude. or dualitude. Do you realize that I was on the verge of accomplishing something that I haven't achieved in thirty years? Twice in a row. Twice in ten minutes."

"There'll be other opportunities. Listen, Barton, I've been to the palace. I've met your son. He's a woman, your age or older, and she's surrounded by fellow illuders, including your former servant. But I can't get anything out of them. They're a bit alarmed, in fact. They know that I know them; they've had a taste of what I can do. Within a week they'll be able to notify others, and I'll never be able to stay ahead of them. Do you understand the situation?"

"You bollixed it up."

"I took a chance and it missed. So now, since you were stupid enough to come here after you promised to stay in Humping--"

"Humping," he said wistfully.

"You might as well make yourself useful. I need to know where they come from. I need to know their homeland. Because unless we strike there, first and hard, we'll never stop them."

He began thinking at once.

"Well, Lanik, it's plain enough that we can't just pull numbers out of a hat and hope to find them. There are eighty Families-- it could be any one of them."

"There are ways to narrow it down. I've got a theory, a good one, I think, about what the Families are doing. In Nkumai I found a history of sorts. It listed what the different Families' founders specialized in. Nkumai, for example, was founded by a physicist. Their export product is physical and astronomical theory. In Mueller we exported the product of genetic research-- the first Mueller was a geneticist. You see?"

"How constant is that?"

"I haven't visited that many countries and been informed what their export product is. But it held true for Ku Kuei and Schwartz."

"A philosopher and a geologist."

I must have looked startled.

"I don't know why the information should surprise you. Britton was founded by a historian. Not a very likely field to turn into a viable export product, but we're fanatics about keeping records. The list of the original eighty traitors from Anderson to Wynn is memorized by every schoolchild, along with brief biographies that include their occupations. We're very thorough. I can also recite my genealogy from Britton himself to me. I haven't done so up to now because you haven't asked me to."

"I never will. You're a man of iron, Barton."

"The question is, what occupation could possibly have led to a Family becoming illuders? Psychologists would be most obvious, wouldn't they? Who was a psychologist? Drew, of course, but they live in their hovels in the north and have dreams of killing their fathers and sleeping with their mothers."

"That could be an illusion," I said.

"Only last year they attacked Arven across the mountains and were humiliatingly defeated. Does that sound like our enerny?"

I shrugged. How could we tell anything about the illuders?

"Besides, they've made little secret of what they've been working on for centuries. Somewhere along the line, the people we're looking for would have to have become secretive. Don't you think? Another psychologist, the only other one, was Hanks. I know nothing about them except that they rebelled against the East Alliance two years ago and my loving son went in with an army and burned the whole country to the ground. The stories said that only one in three people survived, and they lived by getting over the borders and living on charity in Leishman and Parker and Underwood. There is no charity in Gill. Again, it doesn't seem to be a likely spot for the illuders' homeland.

Again, he was right. "No more psychologists?"

"No."

"What other professions then?"

"Maybe they're an exception to your theory, Lanik. Maybe they came up with something new."

"Go through the list. We've got to try to find the most likely prospect, anyway."

So we went through the list. It was tedious, but he wrote it down, in a beautiful script that gave me even more respect for his education, though I could hardly read it. Our guesses were long shots. Tellerman was an actor, but that Family was well known to have literary pretensions. The Ambassador had rejected every book and play and poem they had offered in three thousand years. Their persistence was remarkable. There had been no illusionists or magicians among the original group exiled here, of course-- that was too crass a profession, since the rebellion had been a revolt of the elite against their exploitation by the democratic tyranny of the masses. With a few exceptions, the exiles on Treason were the cream of the cream, the prime intellects of the Republic. Which meant that except for the psychologists and a few other peripheral ones, probably involved in funding the revolt, most of the rebels were experts in a science.

When we had spent more than an hour exhausting, as we thought, every possibility, the answer suddenly seemed so obvious I couldn't believe we had overlooked it until now.

"Anderson," I said.

"We don't even know what he did," Barton said.

"As a profession, we don't. And yet he was head of the rebellion, wasn't he?"

"'Of traitors, traitor most foul,'" Barton intoned.

"Leader of the intellectuals, and yet not an intellectual hiniself."

"Yes. One of the inscrutable facts in history."

"A politician," I said. "A demagogue who got himself elected to the Republic Council, and yet the same man was able to win the trust of the finest minds of the Republic. Isn't that a contradiction?"