Suddenly—wrenching my mind back to the problem I faced—I thought of a possible means of testing the wall’s height, or at least of finding whether or not it extended indefinitely upward. Seizing a handful of mud, I let it drain until it gained some coherence and then flung it high in the air toward the utterly transparent barrier. At a height of perhaps fourteen feet it struck the invisible surface with a resounding splash, disintegrating at once and oozing downward in disappearing streams with surprising rapidity. Plainly, the wall was a lofty one. A second handful, hurled at an even sharper angle, hit the surface about eighteen feet from the ground and disappeared as quickly as the first.
I now summoned up all my strength and prepared to throw a third handful as high as I possibly could. Letting the mud drain, and squeezing it to maximum dryness, I flung it up so steeply that I feared it might not reach the obstructing surface at all. It did, however, and this time it crossed the barrier and fell in the mud beyond with a violent splattering. At last I had a rough idea of the height of the wall, for the crossing had evidently occurred some twenty or twenty-one feet aloft.
With a nineteen- or twenty-foot vertical wall of glassy flatness, ascent was clearly impossible. I must, then, continue to circle the barrier in the hope of finding a gate, an ending, or some sort of interruption. Did the obstacle form a complete round or other closed figure, or was it merely an arc or semi-circle? Acting on my decision, I resumed my slow leftward circling, moving my hands up and down over the unseen surface on the chance of finding some window or other small aperture. Before starting, I tried to mark my position by kicking a hole in the mud, but found the slime too thin to hold any impression. I did, though, gauge the place approximately by noting a tall cycad in the distant forest which seemed just on a line with the gleaming crystal a hundred yards away. If no gate or break existed I could now tell when I had completely circumnavigated the wall.
I had not progressed far before I decided that the curvature indicated a circular enclosure of about a hundred yards’ diameter—providing the outline was regular. This would mean that the dead man lay near the wall at a point almost opposite the region where I had started. Was he just inside or just outside the enclosure? This I would soon ascertain.
As I slowly rounded the barrier without finding any gate, window, or other break, I decided that the body was lying within. On closer view the features of the dead man seemed vaguely disturbing. I found something alarming in his expression, and in the way the glassy eyes stared. By the time I was very near I believed I recognized him as Dwight, a veteran whom I had never known, but who was pointed out to me at the post last year. The crystal he clutched was certainly a prize—the largest single specimen I had ever seen.
I was so near the body that I could—but for the barrier—have touched it, when my exploring left hand encountered a corner in the unseen surface. In a second I had learned that there was an opening about three feet wide, extending from the ground to a height greater than I could reach. There was no door, nor any evidence of hinge marks bespeaking a former door. Without a moment’s hesitation I stepped through and advanced two paces to the prostrate body—which lay at right angles to the hallway I had entered, in what seemed to be an intersecting, doorless corridor. It gave me a fresh curiosity to find that the interior of this vast enclosure was divided by partitions.
Bending to examine the corpse, I discovered that it bore no wounds. This scarcely surprised me, since the continued presence of the crystal argued against the pseudo-reptilian natives. Looking about for some possible cause of death, my eyes lit upon the oxygen mask lying close to the body’s feet. Here, indeed, was something significant. Without this device, no human being could breathe the air of Venus for more than thirty seconds, and Dwight—if it were he—had obviously lost his. Probably it had been carelessly buckled, so that the weight of the tubes worked the straps loose—a thing which could not happen with a Dubois sponge-reservoir mask. The half-minute of grace had been too short to allow the man to stoop and recover his protection—or else the cyanogen content of the atmosphere was abnormally high at the time. Probably he had been busy admiring the crystal—wherever he may have found it. He had, apparently, just taken it from the pouch in his suit, for the flap was unbuttoned.
I now proceeded to extricate the huge crystal from the dead prospector’s fingers—a task which the body’s stiffness made very difficult. The spheroid was larger than a man’s fist, and glowed as if alive in the reddish rays of the westering sun. As I touched the gleaming surface I shuddered involuntarily—as if by taking this precious object I had transferred to myself the doom which had overtaken its earlier bearer. However, my qualms soon passed, and I carefully buttoned the crystal into the pouch of my leather suit. Superstition has never been one of my failings.
Placing the man’s helmet over his dead, staring face, I straightened up and stepped back through the unseen doorway to the entrance hall of the great enclosure. All my curiosity about the strange edifice now returned, and I racked my brain with speculations regarding its material, origin, and purpose. That the hands of men had reared it I could not for a moment believe. Our ships first reached Venus only seventy-two years ago, and the only human beings on the planet have been those at Terra Nova. Nor does human knowledge include any perfectly transparent, non-refractive solid such as the substance of this building. Prehistoric human invasions of Venus can be pretty well ruled out, so that one must turn to the idea of native construction. Did a forgotten race of highly-evolved beings precede the man-lizards as masters of Venus? Despite their elaborately-built cities, it seemed hard to credit the pseudo-reptiles with anything of this kind. There must have been another race aeons ago, of which this is perhaps the last relique. Or will other ruins of kindred origin be found by future expeditions? The purpose of such a structure passes all conjecture—but its strange and seemingly non-practical material suggests a religious use.
Realising my inability to solve these problems, I decided that all I could do was to explore the invisible structure itself. That various rooms and corridors extended over the seemingly unbroken plain of mud, I felt convinced; and I believed that a knowledge of their plan might lead to something significant. So, feeling my way back through the doorway and edging past the body, I began to advance along the corridor toward those interior regions whence the dead man had presumably come. Later on I would investigate the hallway I had left.
Groping like a blind man despite the misty sunlight, I moved slowly onward. Soon the corridor turned sharply and began to spiral in toward the centre in ever-diminishing curves. Now and then my touch would reveal a doorless intersecting passage, and I several times encountered junctions with two, three, and four diverging avenues. In these latter cases I always followed the inmost route, which seemed to form a continuation of the one I had been traversing. There would be plenty of time to examine the branches after I had reached and returned from the main regions. I can scarcely describe the strangeness of the experience—threading the unseen ways of an invisible structure reared by forgotten hands on an alien planet!
At last, still stumbling and groping, I felt the corridor end in a sizeable open space. Fumbling about, I found I was in a circular chamber about ten feet across; and from the position of the dead man against certain distant forest landmarks, I judged that this chamber lay at or near the centre of the edifice. Out of it opened five corridors besides the one through which I had entered, but I kept the latter in mind by sighting very carefully past the body to a particular tree on the horizon as I stood just within the entrance.
There was nothing in this room to distinguish it—merely the floor of thin mud which was everywhere present. Wondering whether this part of the building had any roof, I repeated my experiment with an upward-flung handful of mud, and found at once that no covering existed. If there had ever been one, it must have fallen long ago, for not a trace of debris or scattered blocks ever halted my feet. As I reflected, it struck me as distinctly odd that this apparently primor
dial structure should be so devoid of tumbling masonry, gaps in the walls, and other common attributes of dilapidation.
What was it? What had it ever been? Of what was it made? Why was there no evidence of separate blocks in the glassy, bafflingly homogeneous walls? Why were there no traces of doors, either interior or exterior? I knew only that I was in a round, roofless, doorless edifice of some hard, smooth, perfectly transparent, non-refractive and non-reflective material, a hundred yards in diameter, with many corridors, and with a small circular room at the centre. More than this I could never learn from a direct investigation.
I now observed that the sun was sinking very low in the west—a golden-ruddy disc floating in a pool of scarlet and orange above the mist-clouded trees of the horizon. Plainly, I would have to hurry if I expected to choose a sleeping-spot on dry ground before dark. I had long before decided to camp for the night on the firm, mossy rim of the plateau near the crest whence I had first spied the shining crystal, trusting to my usual luck to save me from an attack by the man-lizards. It has always been my contention that we ought to travel in parties of two or more, so that someone can be on guard during sleeping hours, but the really small number of night attacks makes the Company careless about such things. Those scaly wretches seem to have difficulty in seeing at night, even with curious glow torches.
Having picked out again the hallway through which I had come, I started to return to the structure’s entrance. Additional exploration could wait for another day. Groping a course as best I could through the spiral corridor—with only general sense, memory, and a vague recognition of some of the ill-defined weed patches on the plain as guides—I soon found myself once more in close proximity to the corpse. There were now one or two farnoth-flies swooping over the helmet-covered face, and I knew that decay was setting in. With a futile instinctive loathing I raised my hand to brush away this vanguard of the scavengers—when a strange and astonishing thing became manifest. An invisible wall, checking the sweep of my arm, told me that—notwithstanding my careful retracing of the way—I had not indeed returned to the corridor in which the body lay. Instead, I was in a parallel hallway, having no doubt taken some wrong turn or fork among the intricate passages behind.
Hoping to find a doorway to the exit hall ahead, I continued my advance, but presently came to a blank wall. I would, then, have to return to the central chamber and steer my course anew. Exactly where I had made my mistake I could not tell. I glanced at the ground to see if by any miracle guiding footprints had remained, but at once realised that the thin mud held impressions only for a very few moments. There was little difficulty in finding my way to the centre again, and once there I carefully reflected on the proper outward course. I had kept too far to the right before. This time I must take a more leftward fork somewhere—just where, I could decide as I went.
As I groped ahead a second time I felt quite confident of my correctness, and diverged to the left at the junction I was sure I remembered. The spiralling continued, and I was careful not to stray into any intersecting passages. Soon, however, I saw to my disgust that I was passing the body at a considerable distance; this passage evidently reached the outer wall at a point much beyond it. In the hope that another exit might exist in the half of the wall I had not yet explored, I pressed forward for several paces, but eventually came once more to a solid barrier. Clearly, the plan of the building was even more complicated than I had thought.
I now debated whether to return to the centre again or whether to try some of the lateral corridors extending toward the body. If I chose this second alternative, I would run the risk of breaking my mental pattern of where I was; hence I had better not attempt it unless I could think of some way of leaving a visible trail behind me. Just how to leave a trail would be quite a problem, and I ransacked my mind for a solution. There seemed to be nothing about my person which could leave a mark on anything, nor any material which I could scatter—or minutely subdivide and scatter.
My pen had no effect on the invisible wall, and I could not lay a trail of my precious food tablets. Even had I been willing to spare the latter, there would not have been even nearly enough—besides which the small pellets would have instantly sunk from sight in the thin mud. I searched my pockets for an old-fashioned note-book—often used unofficially on Venus despite the quick rotting-rate of paper in the planet’s atmosphere—whose pages I could tear up and scatter, but could find none. It was obviously impossible to tear the tough, thin metal of this revolving decay-proof record scroll, nor did my clothing offer any possibilities. In Venus’s peculiar atmosphere I could not safely spare my stout leather suit, and underwear had been eliminated because of the climate.
I tried to smear mud on the smooth, invisible walls after squeezing it as dry as possible, but found that it slipped from sight as quickly as did the height-testing handfuls I had previously thrown. Finally I drew out my knife and attempted to scratch a line on the glassy, phantom surface—something I could recognize with my hand, even though I would not have the advantage of seeing it from afar. It was useless, however, for the blade made not the slightest impression on the baffling, unknown material.
Frustrated in all attempts to blaze a trail, I again sought the round central chamber through memory. It seemed easier to get back to this room than to steer a definite, predetermined course away from it, and I had little difficulty in finding it anew. This time I listed on my record scroll every turn I made—drawing a crude hypothetical diagram of my route, and marking all diverging corridors. It was, of course, maddeningly slow work when everything had to be determined by touch, and the possibilities of error were infinite; but I believed it would pay in the long run.
The long twilight of Venus was thick when I reached the central room, but I still had hopes of gaining the outside before dark. Comparing my fresh diagram with previous recollections, I believed I had located my original mistake, so once more set out confidently along the invisible hallways. I veered further to the left than during my previous attempts, and tried to keep track of my turnings on the record scroll in case I was still mistaken. In the gathering dusk I could see the dim line of the corpse, now the centre of a loathsome cloud of farnoth-flies. Before long, no doubt, the mud-dwelling sificlighs would be oozing in from the plain to complete the ghastly work. Approaching the body with some reluctance, I was preparing to step past it when a sudden collision with a wall told me I was again astray.
I now realized plainly that I was lost. The complications of this building were too much for offhand solution, and I would probably have to do some careful checking before I could hope to emerge. Still, I was eager to get to dry ground before total darkness set in; hence I returned once more to the centre and began a rather aimless series of trials and errors—making notes by the light of my electric lamp. When I used this device, I noticed with interest that it produced no reflection—not even the faintest glistening—in the transparent walls around me. I was, however, prepared for this; since the sun had at no time formed a gleaming image in the strange material.
I was still groping about when the dusk became total. A heavy mist obscured most of the stars and planets, but the earth was plainly visible as a glowing, bluish-green point in the southeast. It was just past opposition, and would have been a glorious sight in a telescope. I could even make out the moon beside it whenever the vapours momentarily thinned. It was now impossible to see the corpse—my only landmark—so I blundered back to the central chamber after a few false turns. After all, I would have to give up hope of sleeping on dry ground. Nothing could be done till daylight, and I might as well make the best of it here. Lying down in the mud would not be pleasant, but in my leather suit it could be done. On former expeditions I had slept under even worse conditions, and now sheer exhaustion would help to conquer repugnance.
So here I am, squatting in the slime of the central room and making these notes on my record scroll by the light of the electric lamp. There is something almost humorous in my strange, unpreced
ented plight. Lost in a building without doors—a building which I cannot see! I shall doubtless get out early in the morning, and ought to be back at Terra Nova with the crystal by late afternoon. It certainly is a beauty—with surprising lustre even in the feeble light of this lamp. I have just had it out examining it. Despite any fatigue, sleep is slow in coming, so I find myself writing at great length. I must stop now. Not much danger of being bothered by those cursed natives in this place. The thing I like least is the corpse—but fortunately my oxygen mask saves me from the worst effects. I am using the chlorate cubes very sparingly. Will take a couple of food tablets now and turn in. More later.
LATER—AFTERNOON, VI, 13
There has been more trouble than I expected. I am still in the building, and will have to work quickly and wisely if I expect to rest on dry ground tonight. It took me a long time to get to sleep, and I did not wake till almost noon today. As it was, I would have slept longer but for the glare of the sun through the haze. The corpse was a rather bad sight—wriggling with sificlighs, and with a cloud of farnoth-flies around it. Something had pushed the helmet away from the face, and it was better not to look at it. I was doubly glad of my oxygen mask when I thought of the situation.
At length I shook and brushed myself dry, took a couple of food tablets, and put a new potassium chlorate cube in the electrolyser of the mask. I am using these cubes slowly, but wish I had a larger supply. I felt much better after my sleep, and expected to get out of the building very shortly.