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 weltering 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 brains 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.
Realizing 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 primordial 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 homogenous 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 corridors – 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 his 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 realized 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 a 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.
