Yet most of the city, supposedly built before the evolution of mankind on Earth, appeared untouched by the ages. The dry weather could account in part for that; there were no storms here, and rain had not fallen since Muller's arrival. But wind and windblown sand could carve walls and pavements over a million years, and there was no sign of such carving here. Nor had sand accumulated in the open streets of the city. Muller knew why. Hidden pumps collected all debris, keeping everything spotless. He had gathered handfuls of soil from the garden plots, scattering little trails here and there. Within minutes the driblets of soil had begun to slither across the polished pavement, vanishing into slots that opened briefly and closed again at the intersection of buildings and ground.
Evidently beneath the city lay a network of inconceivable machinery—imperishable caretaker devices that guarded the city against the tooth of time. Muller had not been able to reach that network, though. He lacked the equipment for breaching the pavement; it seemed invulnerable at all points. With improvised tools he had begun to dig in the garden areas, hoping to reach the sub-city that way, but though he had driven one pit more than a dozen feet and another even deeper he had come upon no signs of anything below but more soil. The hidden guardians had to be there, however: the instruments that operated the viewing tanks, swept the streets, repaired the masonry, and controlled the murderous traps that studded the outer zones of the labyrinth.
It was hard to imagine a race that could build a city of this sort —a city designed to last millions of years. It was harder still to imagine how they could have vanished. Assuming that the fossils found in the burial yards outside the walls were those of the builders—not necessarily a safe assumption—this city had been put together by burly humanoids a meter and a half tall, immensely thick through the chest and shoulders, with long cunning fingers, eight to the hand, and short double-jointed legs.
They were gone from the known worlds of the universe, and nothing like them had been found in any other system; perhaps they had withdrawn to some far galaxy yet unvisited by man. Or, possibly, they had been a nonspacegoing race that evolved and perished right here on Lemnos, leaving this city as their only monument.
The rest of the planet was without trace of habitation although burial grounds had been discovered in a diminishing series radiating outward a thousand kilometers from the maze. Maybe the years had eroded all their cities except this one. Maybe this, which could have sheltered perhaps a million beings, had been their only city. There was no clue to their disappearance. The devilish ingenuity of the maze argued that in their last days they had been harassed by enemies and had retreated within this tricky fortress; but Muller knew that this hypothesis too was a speculation. For all he was aware, the maze represented nothing more than an outburst of cultural paranoia and had no relation to the actual existence of an external threat.
Had they been invaded by beings for whom the maze posed no problems, and had they been slaughtered in their own sleek streets, and had the mechanical wardens swept away the bones? No way of knowing. They were gone. Muller, entering their city, had found it silent, desolate, as if it had never sheltered life; an automatic city, sterile, flawless. Only beasts occupied it. They had had a million years to find their way through the maze and take possession. Muller had counted some two dozen species of mammals in all sizes from rat-equivalent to elephant-equivalent. There were grazers who munched on the city's gardens, and hunters who fed on the herbivores, and the ecological balance seemed perfect. The city in the maze was like unto Isaiah's Babylon: wild beasts of the desert shall lie there; and their houses shall be full of doleful creatures; and owls shall dwell there, and satyrs shall dance there.
The city was his now. He had the rest of his lifetime to probe its mysteries.
There had been others who had come here, and not all of them had been human. Entering the maze, Muller had been treated to the sight of those who had failed to go the route. He had sighted a score of human skeletons in Zones H, G, and F. Three men had made it to E, and one to D. Muller had expected to see their bones; but what took him off guard was the collection of alien bones. In H and G he had seen the remains of great dragon-like creatures, still clad in the shreds of spacesuits. Some day curiosity might triumph over fear and he might go back out there for a second look at them. Closer to the core lay an assortment of life-forms, mostly humanoid but veering from the standard structure. How long ago they had come here, Muller could not guess; even in this dry climate, would exposed skeletons last more than a few centuries? The galactic litter was a sobering reminder of something Muller already adequately knew: that despite the experience of man's first two centuries of extrasolar travel, in which no living intelligent alien race was encountered, the universe was full of other forms of life, and sooner or later man would meet them. The boneyard on Lemnos contained relics of at least a dozen different races. It flattered Muller's ego to know that he alone, apparently, had reached the heart of the maze; but it did not cheer him to think of the diversity of peoples in the universe. He had already had his fill of galactics.
The inconsistency of finding the litter of bones within the maze did not strike him for several years. The mechanisms of the city, he knew, cleaned relentlessly, tidying up everything from particles of dust to the bones of the animals on whom he fed. Yet the skeletons of would-be invaders of the maze were allowed to remain where they lay. Why the violation of neatness? Why cart away the corpse of a dead elephant-like beast that had blundered into a power snare, and leave the remains of a dead dragon killed by the same snare? Because the dragon wore protective clothing, and so was sapient? Sapient corpses were deliberately allowed to remain, Muller realized.
As warnings. ABANDON ALL HOPE, YE WHO ENTER HERE.
Those skeletons were part of the psychological warfare waged against all intruders by this mindless, deathless, diabolical city. They were reminders of the perils that lurked everywhere. How the guardian drew the subtle distinction between bodies that should be left in situ and those that should be swept away, Muller did not know; but he was convinced that the distinction was real.
He watched his screens. He eyed the tiny figures moving about the ship on the plain.
Let them come in, he thought. The city hasn't had a victim in years. It'll take care of them. I'm safe where I am.
And, he knew, that even if by some miracle they managed to reach him, they would not remain long. His own special malady would drive them away. They might be clever enough to defeat the maze, but they could not endure the affliction that made Richard Muller intolerable to his own species.
"Go away," Muller said aloud.
He heard the whirr of rotors, and stepped from his dwelling to see a dark shadow traverse the plaza. They were scouting the maze from the air. Quickly he went indoors, then smiled at his own impulse to hide. They could detect him, of course, wherever he was. Their screens would tell them that a human being inhabited the labyrinth. And then, naturally, they would in their astonishment try to make contact with him although they would not be aware of his identity. After that—
Muller stiffened as a sudden overwhelming desire blazed through him. To have them come to him. To talk to men again. To break his isolation.
He wanted them here.
Only for an instant. After the momentary breakthrough of loneliness came the return of rationality—the chilling awareness of what it would be like to face his kind again. No, he thought. Keep out! Or die in the maze. Keep out. Keep out. Keep out.
2
"Right down there," Boardman said. "That's where he must be, eh, Ned? You can see the glow on the face of the tank. We're picking up the right mass, the right density, the right everything. One live man, and it's got to be Muller."
"At the heart of the maze," said Rawlins. "So he really did it!"
"Somehow." Boardman peered into the viewing tank. From a height of a couple of kilometers the structure of the inner city was clear. He could make out eight distinct zones, each with its characteristic style of architectu
re; its plazas and promenades; its angling walls; its tangle of streets swirling in dizzyingly alien patterns. The zones were concentric, fanning out from a broad plaza at the heart of it all, and the scoutplane's mass detector had located Muller in a row of low buildings just to the east of the plaza. What Boardman failed to make out was any obvious passage linking zone to zone. There was no shortage of blind alleys, but even from the air the true route was not apparent; what was it like trying to work inward on the ground?
It was all but impossible, Boardman knew. The master data banks in the ship held the accounts of those early explorers who had tried it and failed. Boardman had brought with him every scrap of information on the penetration of the maze, and none of it was very encouraging except the one puzzling but incontrovertible datum that Richard Muller had managed to get inside.
Rawlins said, "This is going to sound naive, I know, Charles.
But why don't we just come down from here and land the scout-plane in the middle of that central plaza?"
"Let me show you," said Boardman.
He spoke a command. A robot drone probe detached itself from the belly of the plane and streaked toward the city. Board-man and Rawlins followed the flight of the blunt gray metal projectile until it was only a few score meters above the tops of the buildings. Through its faceted eye they had a sharp view of the city, revealing the intricate texture of much of the stonework. Suddenly the drone probe vanished. There was a burst of incandescence, a puff of greenish smoke—and then nothing at all.
Boardman nodded. "Nothing's changed. There's still a protective field over the whole thing. It volatilizes anything that tries to get through."
"So even a bird that comes too close—"
"There are no birds on Lemnos."
"Raindrops, then. Whatever falls on the city—"
"Lemnos gets no rain," said Boardman sourly. "At least not on this continent. The only thing that field keeps out is strangers. We've known it since the first expedition. Some brave men found out about that field the hard way."
"Didn't they try a drone probe first?"
Smiling, Boardman said, "When you find a dead city in the middle of a desert on a dead world you don't expect to be blown up if you land inside it. It's a forgivable sort of mistake—except that Lemnos doesn't forgive mistakes." He gestured, and the plane dropped lower, following the orbit of the outer walls for a moment. Then it rose and hovered over the heart of the city while photographs were being taken. The wrong-colored sunlight glistened off a hall of mirrors. Boardman felt curdled weariness in his chest. They overflew the city again and again, marking off a preprogrammed observation pattern, and he discovered he was wishing irritably that a shaft of sudden light would rise from those mirrors and incinerate them on the next pass to save him the trouble of carrying out this assignment. He had lost his taste for detail-work, and too many fine details stood between him and his purpose here. They said that impatience was a mark of youth, that old men could craftily spin their webs and plot their schemes in serenity, but somehow Boardman found himself longing rashly for a quick consummation to this job. Send some sort of drone scuttling through the maze on metal tracks to seize Muller and drag him out. Tell the man what was wanted of him and make him agree to do it. Then take off for Earth, quickly, quickly. The mood passed. Boardman felt foxy again.
Captain Hosteen, who would be conducting the actual entry attempt, came aft to pay his respects. Hosteen was a short, thick-framed man with a flat nose and coppery skin; he wore his uniform as though he felt it was all going to slip off his left shoulder at any moment. But he was a good man, Boardman knew, and ready to sacrifice a score of lives, including his own, to get into that maze.
Hosteen flicked a glance from the screen to Boardman's face and said, "Learning anything?"
"Nothing new. We have a job."
"Want to go down again?"
"Might as well," Boardman said. He looked at Rawlins. "Unless you have anything else you'd like to check, Ned?"
"Me? Oh, no—no. That is—well, I wonder if we need to go into the maze at all. I mean, if we could lure Muller out somehow, talk to him outside the city—"
"No."
"Wouldn't it work?"
"No," said Boardman emphatically. "Item one, Muller wouldn't come out if we asked him. He's a misanthrope. Remember? He buried himself here to get away from humanity. Why should he socialize with us? Item two, we couldn't invite him outside without letting him know too much about what we want from him. In this deal, Ned, we need to hoard our resources of strategy, not toss them away in our first move."
"I don't understand what you mean."
Patiently Boardman said, "Suppose we used your approach. What would you say to Muller to make him come out?"
"Why—that we're here from Earth to ask him if he'll help us in a time of system-wide crisis. That we've encountered a race of alien beings with whom we're unable to communicate, and that it's absolutely necessary that we break through to them in a hurry, and that he alone can do the trick. We—" Rawlins stopped, as though the fatuity of his own words had broken through to him. Color mounted in his cheeks. He said in a hoarse voice, "Muller isn't going to give a damn for those arguments, is he?"
"No, Ned. Earth sent him before a bunch of aliens once before, and they ruined him. He isn't about to try it again."
"Then how are we going to make him help us?"
"By playing on his sense of honor. But at the moment that's not the problem we're talking about. We're discussing how to get him out of his sanctuary in there. Now, you were suggesting that we set up a speaker and tell him exactly what we want from him, and then wait for him to waltz out and pledge to do his best for good old Earth. Right?"
"I guess so."
"But it won't work. Therefore we've got to get inside the maze ourselves, win Muller's trust, and persuade him to cooperate. And to do that we have to keep quiet about the real situation until we've eased him out of his suspicions."
A look of newborn wariness appeared on Rawlins' face. "What are we going to tell him, then, Charles?"
"Not we. You."
"What am I going to tell him, then?" Boardman sighed. "Lies, Ned. A pack of lies."
3
They had come equipped for solving the problem of the maze. The ship's brain, of course, was a first-class computer, and it carried the details of all previous Earth-based attempts to enter the city. Except one, and unfortunately that had been the only successful one. But records of past failures have their uses. The ship's data banks had plenty of mobile extensions: airborne and groundborne drone probes, spy-eyes, sensor batteries, and more. Before any human life was risked on the maze Boardman and Hosteen would try the whole mechanical array. Mechanicals were expendable, anyway; the ship carried a set of templates, and it would be no trouble to replicate all devices destroyed. But a point would come at which the drone probes had to give way to men: the aim was to gather as much information as possible for those men to use.
Never before had anyone tried to crack the maze this way. The early explorers had simply gone walking in, unsuspecting, and had perished. Their successors had known enough of the story to avoid the more obvious traps, and to some extent had been aided by sophisticated sensory devices, but this was the first attempt to run a detailed survey before entering. No one was overly confident that the technique would let them in unscathed, but it was the best way to approach the problem.
The overflights on the first day had given everybody a good visual image of the maze. Strictly speaking, it hadn't been necessary for them to leave the ground; they could have watched big-screen relays from the comfort of their camp and gained a decent idea of the conformation below, letting airborne probes do all the work. But Boardman had insisted. The mind registers things one way when it picks them off a relay screen, and another when the sensory impressions are flooding in straight from the source. Now they all had seen the city from the air, and had seen what the guardians of the maze could do to a drone probe that ventured i
nto the protective field overlying the city.
Rawlins had suggested the possibility that there might be a null spot in that protective field. Toward late afternoon they checked it out by loading a probe with metal pellets and stationing it fifty meters above the highest point of the maze. Scanner eyes recorded the action as the drone slowly turned, spewing the pellets one at a time into preselected one-square-meter boxes above the city. Each in turn was incinerated as it fell. They were able to calculate that the thickness of the safety field varied with distance from the center of the maze; it was only about two meters deep above the inner zones, much deeper at the outer rim, forming an invisible cup over the city. But there were no null spots; the field was continuous. Hosteen tested the notion that the field was capable of overstrain by having the probe reloaded with pellets which were catapulted simultaneously into each of the test rectangles. The field dealt with them all, creating for a moment a single pucker of flame above the city.
At the expense of a few mole probes they found out that reaching the city through a tunnel was equally impossible. The moles burrowed into the coarse sandy soil outside the outer walls, chewed themselves passageways fifty meters down, and nosed upward again when they were beneath the maze. They were destroyed by the safety field while still twenty meters below ground level. A try at burrowing in right at the base of the embankments also failed; the field went straight down, apparently, all around the city.
A power technician offered to rig an interference pylon to drain the energy of the field. It didn't work. The pylon, a hundred meters tall, sucked in power from all over the planet; blue lightning leaped and hissed along its accumulator bank, but it had no effect on the safety field. They reversed the pylon and sent a million kilowatts shooting into the city, hoping to short the field. The field drank everything and seemed ready for more. No one had any rational theory to explain the field's power source. "It must tap the planet's own energy of rotation," the technician who had rigged the pylon said, and then, realizing he hadn't contributed anything useful, he looked away and began to snap orders into the hand-mike he carried.