First Level—complete success, and colony fully established. The Fifth Level is the probability of complete failure—no human population established on this planet, and indigenous quasi-human life evolved indigenously. On the Fourth Level, the colonists evidently met with some disaster and lost all memory of their extraterrestrial origin, as well as all extraterrestrial culture. As far as they know, they are an indigenous race; they have a long pre-history of stone-age savagery.
"Sectors are areas of paratime on any level in which the prevalent culture has a common origin and common characteristics. They are divided more or less arbitrarily into sub-sectors. Belts are areas within sub-sectors where conditions are the result of recent alternate probabilities. For instance, I've just come from the Europo-American Sector of the Fourth Level, an area of about ten thousand parayears in depth, in which the dominant civilization developed on the North-West Continent of the Major Land Mass, and spread from there to the Minor Land Mass. The line on which I was operating is also part of a sub-sector of about three thousand parayears' depth, and a belt developing from one of several probable outcomes of a war concluded about three elapsed years ago. On that time-line, the field at the Hagraban Synthetics Works, where we took off, is part of an abandoned farm; on the site of Hagraban City is a little farming village. Those things are there, right now, both in primary time and in the plenum. They are about two hundred and fifty thousand parayears perpendicular to each other, and each is of the same general order of reality."
The red light overhead flashed on. The pilot looked into his visor and put his hands to the manual controls, in case of failure of the robot controls. The rocket landed smoothly, however; there was a slight jar as it was grappled by the crane and hoisted upright, the seats turning in their gimbals. Pilot and passenger unstrapped themselves and hurried through the refrigerated outlet and away from the glowing-hot rocket.
An air-taxi, emblazoned with the device of the Paratime Police, was waiting. Verkan Vall said good-by to the rocket-pilot and took his seat beside the pilot of the aircab; the latter lifted his vehicle above the building level and then set it down on the landing-stage of the Paratime Police Building in a long, side-swooping glide. An express elevator took Verkan Vall down to one of the middle stages, where he showed his sigil to the guard outside the door of Tortha Karf's office and was admitted at once.
The Paratime Police chief rose from behind his semicircular desk, with its array of keyboards and viewing-screens and communicators. He was a big man, well past his two hundredth year; his hair was iron-gray and thinning in front, he had begun to grow thick at the waist, and his calm features bore the lines of middle age. He wore the dark-green uniform of the Paratime Police.
"Well, Vall," he greeted. "Everything secure?"
"Not exactly, sir." Verkan Vall came around the desk, deposited his rifle 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 fill it. "But that's only the beginning. I have to trace something else. Gavran Sarn exceeded his Paratime permit, and took one of his pets along. 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 place of profanity, as the emotional release of a race that has forgotten all the taboos and terminologies of supernaturalistic religion and sex-inhibition.
"You're sure of this, of course." It was less a question than a statement.
Verkan Vall bent and took cloth-wrapped objects from his bag, unwrapping them and laying them on the desk. They were casts, in hard black plastic, 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 angry as 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 or object to any time-line on which space-travel is unknown. I don't care if 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 be coming 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 political importance, that might make difficulties. Not that it wouldn't be all right with me, of course, but we never seem to be able to make either the Management or the public realize the extremities to which we are forced, at times." He sighed. "We probably never shall."
Verkan Vall smiled faintly. "Oh, no, sir; nothing like that. He was dead before I transposed to that time-line. He was killed when he wrecked a self-propelled vehicle he was using. One of those Fourth Level automobiles. I posed as a relative and tried to claim his body for the burial-ceremony observed on that cultural level, but was told that it had been completely destroyed by fire when the fuel tank of this automobile burned. I was given certain of his effects which had passed through the fire; I found his sigil concealed inside what appeared to be a cigarette case." He took a green disk from the bag and laid it on the desk. "There's no question; Gavran Sarn died in the wreck of that automobile."
"And the nighthound?"
"It was in the car with him, but it escaped. You know how fast those things are. I found that track"—he indicated one of the black casts—"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 my field-generator there. It runs through to the Hagraban Synthetics Works, about a hundred miles east of Thalna-Jarvizar. I have my this-line terminal in the girls' rest room at the durable plastics factory; handled that on a local police-power writ. Since then, I've been hunting for the nighthound. I think I can find it, but I'll need some special equipment, 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 forested mountains and valley farms, rather than a built-up industrial district. Local police and wild-game protection officers are concerned; all the farmers excited, and going armed. The theory is that it's either a wildcat of some sort, or a maniac 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 and bring it out, or kill it and obliterate the body. You know why, as well as I do."
"Certainly, sir," Verkan Vall replied. "In a primitive culture, things like this would be assigned supernatural explanations, and imbedded in the locally accepted religion. But this culture, while nominally religious, is highly rationalistic in practice. Typical lag-effect, characteristic of all expanding cultures. And this Europo-American Sector really has an expanding culture. A hundred and fifty years ago, the inhabitants of this particular time-line didn't even know how to apply steam power; now they've begun to release nuclear energy, in a few crude forms."
Tortha Karf whistled, softly. "That's quite a jump. There's a sector that'll be in for trouble, in the next few centuries."
"That is realized, locally, sir." Verkan Vall concentrated on relighting his pipe, for a moment, then continued: "I would predict space-travel on that sector within the next century. Maybe the next half-century, at least to the Moon. And the art of taxidermy is very highly developed. Now, suppose some farmer shoots that thing; what would he do with it, sir?"
Tortha Karf grunted. "Nice logic, Vall. On a most uncomfortable possibility. He'd have it mounted, and it'd be put in a museum, somewhere. And as soon as the first spaceship reaches Venus, and they find those things in a wild state, they'll have the mounted specimen identified."
"Exactly. And then,