point in primarytime--plus primary time elapsed during mechanical and electronic lagin the relays--but a different line of secondary time."
"Then why don't we have past-future time travel on our own time-line?"the pilot wanted to know.
That was a question every paratimer has to answer, every time he talksparatime to the laity. Verkan Vall had been expecting it; he answeredpatiently.
"The Ghaldron-Hesthor field-generator is like every other mechanism; itcan operate only in the area of primary time in which it exists. It cantranspose to any other time-line, and carry with it anything inside itsfield, but it can't go outside its own temporal area of existence, anymore than a bullet from that rifle can hit the target a week before it'sfired," Verkan Vall pointed out. "Anything inside the field is supposedto be unaffected by anything outside. _Supposed to be_ is the way to putit; it doesn't always work. Once in a while, something pretty nasty getspicked up in transit." He thought, briefly, of the man in the blacktunic. "That's why we have armed guards at terminals."
"Suppose you pick up a blast from a nucleonic bomb," the pilot asked,"or something red-hot, or radioactive?"
"We have a monument, at Paratime Police Headquarters, in Dhergabar,bearing the names of our own personnel who didn't make it back. It's alarge monument; over the past ten thousand years, it's been inscribedwith quite a few names."
"You can have it; I'll stick to rockets!" the pilot replied. "Tell meanother thing, though: What's all this about levels, and sectors, andbelts? What's the difference?"
"Purely arbitrary terms. There are five main probability levels, derivedfrom the five possible outcomes of the attempt to colonize this planet,seventy-five thousand years ago. We're on the First Level--completesuccess, and colony fully established. The Fifth Level is theprobability of complete failure--no human population established on thisplanet, and indigenous quasi-human life evolved indigenously. On theFourth Level, the colonists evidently met with some disaster and lostall memory of their extraterrestrial origin, as well as allextraterrestrial culture. As far as they know, they are an indigenousrace; they have a long pre-history of stone-age savagery.
"Sectors are areas of paratime on any level in which the prevalentculture has a common origin and common characteristics. They are dividedmore or less arbitrarily into sub-sectors. Belts are areas withinsub-sectors where conditions are the result of recent alternateprobabilities. For instance, I've just come from the Europo-AmericanSector of the Fourth Level, an area of about ten thousand parayears indepth, in which the dominant civilization developed on the North-WestContinent of the Major Land Mass, and spread from there to the MinorLand Mass. The line on which I was operating is also part of asub-sector of about three thousand parayears' depth, and a beltdeveloping from one of several probable outcomes of a war concludedabout three elapsed years ago. On that time-line, the field at theHagraban Synthetics Works, where we took off, is part of an abandonedfarm; on the site of Hagraban City is a little farming village. Thosethings are there, right now, both in primary time and in the plenum.They are about two hundred and fifty thousand parayears perpendicularto each other, and each is of the same general order of reality."
The red light overhead flashed on. The pilot looked into his visor andput his hands to the manual controls, in case of failure of the robotcontrols. The rocket landed smoothly, however; there was a slight jaras it was grappled by the crane and hoisted upright, the seats turningin their gimbals. Pilot and passenger unstrapped themselves and hurriedthrough the refrigerated outlet and away from the glowing-hot rocket.
* * * * *
An air-taxi, emblazoned with the device of the Paratime Police, waswaiting. Verkan Vall said good-by to the rocket-pilot and took his seatbeside the pilot of the aircab; the latter lifted his vehicle above thebuilding level and then set it down on the landing-stage of the ParatimePolice Building in a long, side-swooping glide. An express elevator tookVerkan Vall down to one of the middle stages, where he showed his sigilto the guard outside the door of Tortha Karf's office and was admittedat once.
The Paratime Police chief rose from behind his semicircular desk, withits array of keyboards and viewing-screens and communicators. He was abig man, well past his two hundredth year; his hair was iron-gray andthinning in front, he had begun to grow thick at the waist, and his calmfeatures bore the lines of middle age. He wore the dark-green uniformof the Paratime Police.
"Well, Vall," he greeted. "Everything secure?"
"Not exactly, sir." Verkan Vall came around the desk, deposited hisrifle and bag on the floor, and sat down in one of the spare chairs."I'll have to go back again."
"So?" His chief lit a cigarette and waited.
"I traced Gavran Sarn." Verkan Vall got out his pipe and began to fillit. "But that's only the beginning. I have to trace something else.Gavran Sarn exceeded his Paratime permit, and took one of his petsalong. A Venusian nighthound."
Tortha Karf's expression did not alter; it merely grew more intense.He used one of the short, semantically ugly terms which serve, in placeof profanity, as the emotional release of a race that has forgotten allthe taboos and terminologies of supernaturalistic religion andsex-inhibition.
"You're sure of this, of course." It was less a question thana statement.
Verkan Vall bent and took cloth-wrapped objects from his bag, unwrappingthem and laying them on the desk. They were casts, in hard blackplastic, of the footprints of some large three-toed animal.
"What do these look like, sir?" he asked.
Tortha Karf fingered them and nodded. Then he became as visibly angryas a man of his civilization and culture-level ever permitted himself.
"What does that fool think we have a Paratime Code for?" he demanded."It's entirely illegal to transpose any extraterrestrial animal orobject to any time-line on which space-travel is unknown. I don't careif he is a green-seal thavrad; he'll face charges, when he gets back,for this!"
"He _was_ a green-seal thavrad," Verkan Vall corrected. "And he won't becoming back."
"I hope you didn't have to deal summarily with him," Tortha Karf said."With his title, and social position, and his family's politicalimportance, that might make difficulties. Not that it wouldn't be allright with me, of course, but we never seem to be able to make eitherthe Management or the public realize the extremities to which we areforced, at times." He sighed. "We probably never shall."
Verkan Vall smiled faintly. "Oh, no, sir; nothing like that. He wasdead before I transposed to that time-line. He was killed when hewrecked a self-propelled vehicle he was using. One of those FourthLevel automobiles. I posed as a relative and tried to claim his bodyfor the burial-ceremony observed on that cultural level, but was toldthat it had been completely destroyed by fire when the fuel tank ofthis automobile burned. I was given certain of his effects which hadpassed through the fire; I found his sigil concealed inside whatappeared to be a cigarette case." He took a green disk from the bagand laid it on the desk. "There's no question; Gavran Sarn died inthe wreck of that automobile."
"And the nighthound?"
"It was in the car with him, but it escaped. You know how fast thosethings are. I found that track"--he indicated one of the blackcasts--"in some dried mud near the scene of the wreck. As you see,the cast is slightly defective. The others were fresh this morning,when I made them."
"And what have you done so far?"
"I rented an old farm near the scene of the wreck, and installed myfield-generator there. It runs through to the Hagraban Synthetics Works,about a hundred miles east of Thalna-Jarvizar. I have my this-lineterminal in the girls' rest room at the durable plastics factory;handled that on a local police-power writ. Since then, I've been huntingfor the nighthound. I think I can find it, but I'll need some specialequipment, and a hypno-mech indoctrination. That's why I came back."
"Has it been attracting any attention?" Tortha Karf asked anxiously.
"Killing cattle in the locality; causing considerable excitement.Fortunately, it's a locality of fo
rested mountains and valley farms,rather than a built-up industrial district. Local police and wild-gameprotection officers are concerned; all the farmers excited, and goingarmed. The theory is that it's either a wildcat of some sort, or amaniac armed with a cutlass. Either theory would conform, more or less,to the nature of its depredations. Nobody has actually seen it."
"That's good!" Tortha Karf was relieved. "Well, you'll have to go andbring it out, or kill it and obliterate the body. You know why, as wellas I do."
"Certainly, sir," Verkan Vall replied. "In a primitive culture,