It was 1530, there, when he got Vulthor Tharn on the screen.

"Good afternoon. a.s.sistant Verkan. I suppose you"re calling about the slave business. I"ve turned the entire matter over to Field Agent Skordran; gave him a temporary rank of Deputy Subchief. That"s subject to your approval and Chief Tortha"s, of course--"

"Make the appointment permanent," Vall said. "I"ll have a confirmation along from Chief Tortha directly. And let me talk to him now, if you please. Subchief Vulthor."

"Yes, sir. Switching you over now." The screen went into a beautiful burst of abstract art, and cleared, after a while, with Skordran Kirv looking out of it.

"h.e.l.lo, Deputy Skordran, and congratulations. What"s come up since we had Nebu-hin-Abenoz cut out from under us?"

"We went in on that time line, that same night, with an airboat and made a recon in the hills back of Careba. Scared the fear of Safar into a party of Caleras while we were working at low alt.i.tude, by the way. We found the conveyer-head site: hundred-foot circle with all the gra.s.s and loose dirt transposed off it and a pole pen, very unsanitary where about two-three hundred slaves would be kept at a time. No indications of use in the last ten days. We did some pretty thorough boomeranging on that spatial equivalent over a couple of thousand time lines and found thirty more of them. I believe the slavers have closed out the whole Esaron Sector operation, at least temporarily."

That was what he"d been afraid of; he hoped they wouldn"t do the same thing on the Kholghoor Sector.

"Let me have the designations of the time lines on which you found conveyer heads," he said.

"Just a moment, Chief"s a.s.sistant; I"ll photoprint them to you. Set for reception?"

Vall opened a slide under the screen and saw that the photoprint film was in place, then closed it again, nodding. Skordran Kirv fed a sheet of paper into his screen cabinet and his arm moved forward out of the picture.

"On, sir," he said. He and Vall counted ten seconds together, and then Skordran Kirv said: "Through to you." Vall pressed a lever under his screen, and a rectangle of microcopy print popped out.

"That"s about all I have, sir. Want me to keep my troops ready here, or shall I send them somewhere else?"

"Keep them ready, Kirv," Vall told him. "You may need them before long. Call you later."

He put the microcopy in an enlarger, and carried the enlarged print with him to the conveyer room. There was something odd about the list of time line designations. They were expressed numerically, in First Level notation; extremely short groups of symbols capable of exact expression of almost inconceivably enormous numbers. Vall had only a general-education smattering of mathematics--enough to qualify him for the chair of Higher Mathematics at any university on, say, the Fourth Level Europo-American Sector--and he could not identify the peculiarity, but he could recognize that there existed some sort of pattern. Shoving in the starting lever, he relaxed in one of the chairs, waiting for the transposition field to build up around him, and fell asleep before the mesh dome of the conveyer had vanished. He woke, the list of time line designations in his hand, when the conveyor rematerialized on Home Time Line. Putting it in his pocket, he hurried to an antigrav shaft and floated up to the floor on which Tortha Karf"s office was.

Tortha Karf was asleep in his chair; Dalla was eating a dinner that had been brought in to her--something better than the sandwich and mug of coffee Vall had mentioned to Thalvan Dras. Several of the bureau chiefs who had been there when he had gone out had left, and the psychist who had taken charge of the prisoner was there.

"I think he"s coming out of the drug, now," he reported. "Still asleep, though. We want him to waken naturally before we start on him.

They"ll call me as soon as he shows signs of stirring."

"The Opposition"s claiming, now, that we drugged and hypnotized Salgath into making that visiscreen confession," Dalla said. "Can you think of any way you could do that without making the subject incapable of lying?"

"Pseudo-memories," the psychist said. "It would take about three times as long as the time between Salgath Trod"s departure from his apartment and the time of the telecast, though--"

"You know much higher math?" Vall asked the psychist.

"Well, enough to handle my job. Neuron-synapse inter-relations, memory-and-a.s.sociation patterns, that kind of thing, all have to be expressed mathematically."

Vall nodded and handed him the time-line designation list.

"See any kind of a pattern there?" he asked.

The psychist looked at the paper and blanked his face as he drew on hypnotically-acquired information.

"Yes. I"d say that all the numbers are related in some kind of a series to some other number. Simplified down to kindergarten level, say the difference between A and B is, maybe, one-decillionth of the difference between X and A, and the difference between B and C is one-decillionth of the difference between X and B, and so on--"

A voice came out of one of the communication boxes:

"Dr. Nentrov; the patient"s out of the drug, and he"s beginning to stir about."

"That"s it," the psychist said. "I have to run." He handed the sheet back to Vall, took a last drink from his coffee cup, and bolted out of the room.

Dalla picked up the sheet of paper and looked at it. Vall told her what it was.

"If those time lines are in regular series, they relate to the base line of operations," she said. "Maybe you can have that worked out. I can see how it would be; a stated interval between the Esaron Sector lines, to simplify transposition control settings."

"That was what I was thinking. It"s not quite as simple as Dr. Nentrov expressed it, but that could be the general idea. We might be able to work out the location of the base line from that. There seems to be a break in the number sequence in here; that would be the time line Skordran Kirv found those slaves on." He reached for the pipe he had left on the desk when he had gone to Police Terminal and began filling it.

A little later, a buzzer sounded and a light came on on one of the communication boxes. He flipped the switch and said, "Verkan Vall here." Sothran Barth"s voice came cut of the box.

"They"ve just brought in Salgath Trod"s servants. Picked them up as they came out of the house conveyer at the apartment building. I don"t believe they know what"s happened."

Vall flipped a switch and twiddled a dial; a viewscreen lit up, showing the landing stage. The police car had just landed: one detective had gotten out, and was helping the girl, Zinganna, who had been Salgath Trod"s housekeeper and mistress, to descend. She was really beautiful. Vall thought: rather tall, slender, with dark eyes and a creamy light-brown skin. She wore a black cloak, and, under it, a black and silver evening gown. A single jewel twinkled in her black hair. She could have very easily pa.s.sed for a woman of his own race.

The housemaid and the butler were a couple of entirely different articles. Both were about four or five generations from Fourth Level Primitive savagery. The maid, in garishly cheap finery, was big-boned and heavy-bodied, with red-brown hair; she looked like a member of one of the northern European reindeer-herding peoples who had barely managed to progress as far as the bow and arrow. The butler was probably a mixture of half a dozen primitive races; he was wearing one of his late master"s evening suits, a bright mellow-pink, which was distinctly unflattering to his complexion.

The sound-pickup was too far away to give him what they were saying, but the butler and maid were waving their arms and protesting vehemently. One of the detectives took the woman by the arm; she jerked it loose and aimed a backhand slap at him. He blocked it on his forearm. Immediately, the girl in black turned and said something to her, and she subsided. Vall said, into the box:

"Barth, have the girl in the black cloak brought down to Number Four Interview Room. Put the other two in separate detention cubicles; we"ll talk to them later." He broke the connection and got to his feet. "Come on, Dalla. I want you to help me with the girl."

"Just try and stop me," Dalla told him. "Any interviews you have with that little item, I want to sit in on."

The Proletarian girl, still guarded by a detective, had already been placed in the interview room. The detective nodded to Vall, tried to suppress a grin when he saw Dalla behind him, and went out. Vall saw his wife and the prisoner seated, and produced his cigarette case, handing it around.

"You"re Zinganna; you"re of the household of Councilman Salgath Trod, aren"t you?" he asked.

"Housekeeper and hostess," the girl replied. "I am also his mistress."

Vall nodded, smiling. "Which confirms my long-standing respect for Councilman Salgath"s exquisite taste."

"Why, thank you," she said. "But I doubt if I was brought here to receive compliments. Or was I?"

"No, I"m afraid not. Have you heard the newscasts of the past few hours concerning Councilman Salgath?"

She straightened in her seat, looking at him seriously.

"No. I and Nindrandigro and Calilla spent the evening on ServSec One-Six-Five. Councilman Salgath told me that he had some business and wanted them out of the apartment, and wanted me to keep an eye on them. We didn"t hear any news at all." She hesitated. "Has anything ... serious ... happened?"

Vall studied her for a moment, then glanced at Dalla. There existed between himself and his wife a sort of vague, semitelepathic, rapport; they had never been able to transmit definite and exact thoughts, but they could clearly prehend one another"s feelings and emotions. He was conscious, now, of Dalla"s sympathy for the Proletarian girl.

"Zinganna, I"m going to tell you something that is being kept from the public," he said. "By doing so, I will make it necessary for us to detain you, at least for a few days. I hope you will forgive me, but I think you would forgive me less if I didn"t tell you."

"Something"s happened to him," she said, her eyes widening and her body tensing.