show the title sheet of a file, marked obliquely with the word RESTRICTED in red. This disappeared to be replaced by a contour map of what looked like a rugged and broken stretch of terrain. A slowly pulsing point of light appeared in the center of the picture and began moving across the map as Caldwell rotated a tracker ball set into the panel that held the keyboard. The light halted at a point where the contours indicated the junction of a steep-sided cleft valley with a wider gorge. The cleft valley was narrow and seemed to branch off from the gorge in a rising curve.
'This map shows the area in question,' the director resumed. 'The cursor shows where a minor cleft joins the main fault running down toward the left. The survey boys left their vehicle at this point and proceeded on up to the cleft on foot, looking for a way to the top of that large rock mass-the one tagged ‘five sixty’.' As Caldwell spoke, the pulsing light moved slowly along between the minor sets of contours, tracing out the path taken by the UN team. They watched it negotiate the bend above the mouth of the cleft and proceed some distance farther. The light approached the side of the cleft and touched it at a place where the contours merged into a single heavy line. There it stopped.
'Here the side was a sheer cliff about sixty feet high. That was where they came across the first thing that was unusual-a hole in the base of the rock wall. The sergeant leading the group described it as being like a cave. That strike you as odd?'
Hunt raised his eyebrows and shrugged. 'Caves don’t grow on moons,' he said simply.
'Exactly.'
The screen now showed a photo view of the area, apparently taken from the spot at which the survey vehicle had been parked. They recognized the break in the wall of the gorge where the cleft joined it. The cleft was higher up than had been obvious from the map and was approached by a ramp of loose rubble. In the background they could see a squat tower of rock flattened on top- presumably the one marked '560' on the map. Caldwell allowed them some time to reconcile the picture with the map before bringing up the second frame. It showed a view taken high up, this time looking into the mouth of the cleft. A series of shots then followed, progressing up to and beyond the bend. 'These are stills from a movie record,' Caldwell commented. 'I won’t bother with the whole set.' The final frame in the sequence showed a hole in the rock about five feet across.
'Holes like this aren’t unknown on the Moon,' Caldwell remarked. 'But they are rare enough to prompt our men into taking a closer look. The inside was a bit of a mess. There had been a rockfall-maybe several falls; not much room-just a heap of rubble and dust… at first sight, anyway.' A new picture on the screen confirmed this statement. 'But when they got to probing around a bit more, they came across something that was really unusual. Underneath they found a body-dead!'
The picture changed again to show another view of the interior, taken from the same angle as the previous one. This time, however, the subject was the top half of a human figure lying amid the rubble and debris, apparently at the stage of being half uncovered. It was clad in a spacesuit which, under the layer of gray-white dust, appeared to be bright red. The helmet seemed intact, but it was impossible to make out any details of the face behind the visor because of the reflected camera light. Caldwell allowed them plenty of time to study the picture and reflect on these facts before speaking again.
'That is the body. I’ll answer some of the more obvious questions before you ask. First-no, we don’t know who he is-or was-so we call him Charlie. Second-no, we don’t know for sure what killed him. Third-no, we don’t know where he came from.' The executive director caught the puzzled look on Hunt’s face and raised his eyebrows inquiringly.
'Accidents can happen, and it’s not always easy to say what caused them-I’ll buy that,' Hunt said. 'But to not know who he is…? I mean, he must have carried some kind of ID card; I’d have thought he’d have to. And even if he didn’t, he must be from one of the UN bases up there. Someone must have noticed he was missing.'
For the first time the flicker of a smile brushed across Caldwell’s face.
'Of course we checked with all the bases, Dr. Hunt. Results negative. But that was just the beginning. You see, when they got him back to the labs for a more thorough check, a number of peculiarities began to emerge which the experts couldn’t explain-and, believe me, we’ve had enough brains in on this. Even after we brought him back here, the situation didn’t get any better. In fact, the more we find out, the worse it gets.'
'‘Back here’? You mean…
'Oh, yes. Charlie’s been shipped back to Earth. He’s over at the Westwood Biological Institute right now-a few miles from here. We’ll go and have a look at him later on today.'
Silence reigned for what seemed like a long time as Hunt and Gray digested the rapid succession of new facts. At last Gray offered:
'Maybe someobody dumped him for some reason?'
'No, Mr. Gray, you can forget anything like that.' Caldwell waited a few more seconds. 'Let me say that from what little we do know so far, we can state one or two things with certainty. First, Charlie did not come from any of the bases established to date on Luna. Furthermore'-Caldwell’s voice slowed to an ominous rumble-'he did not originate from any nation of the world as we know it today. In fact, it is by no means certain that he originated from this planet at all!'
His eyes traveled from Hunt to Gray, then back again, taking in the incredulous stares that greeted his words. Absolute silence enveloped the room. A suspense almost audible tore at their nerves. Caldwell’s finger stabbed at the keyboard.
The face leaped out at them from the screen in grotesque closeup, skull-like, the skin shriveled and darkened like ancient parchment, and stretched back over the bones to uncover two rows of grinning teeth. Nothing remained of the eyes but a pair of empty pits, staring sightlessly out through dry, leathery lids.
Caldwell’s voice, now a chilling whisper, hissed through the fragile air.
'You see, gentlemen-Charlie died over fifty thousand years ago!'
Chapter Six
Dr. Victor Hunt stared absently down at the bird’s-eye view of the outskirts of Houston sliding by below the UNSA jet. The mind-numbing impact of Caldwell’s revelations had by this time abated sufficiently for him to begin putting together in his mind something of a picture of what it all meant.
Of Charlie’s age there could be no doubt. All living organisms take into their bodies known proportions of the radioactive isotopes of carbon and certain other elements. During life, an organism maintains a constant ratio of these isotopes to 'normal' ones, but when it dies and intake ceases, the active isotopes are left to decay in a predictable pattern. This mechanism provides, in effect, a highly reliable clock, which begins to run at the moment of death. Analysis of the decay residues enables a reliable figure to be calculated for how long the clock has been running. Many such tests had been performed on Charlie, and all the results agreed within close limits.
Somebody had pointed out that the validity of this method rested on the assumptions that the composition of whatever Charlie ate, and the constituents of whatever atmosphere he breathed, were the same as for modern man on modern Earth. Since Charlie might not be from Earth, this assumption could not be made. It hadn’t taken long, however, for this point to be settled conclusively. Although the functions of most of the devices contained in Charlie’s backpack were still to be established, one assembly had been identified as an ingeniously constructed miniature nuclear power plant. The U235 fuel pellets were easily located and analysis of their decay products yielded a second, independent answer, although a less accurate one: The power unit in Charlie’s backpack had been made some fifty thousand years previously. The further implication of this was that since the first set of test results was thus substantiated, it seemed to follow that in terms of air and food supply, there could have been little abnormal about Charlie’s native environment.
Now, Charlie’s kind, Hunt told himself, must have evolved to their human form somewhere. That this 'somewhere' was either Earth or not Earth was fairly obvious, the rules of basic logic admitting no other possibility. He traced back over what he could recall of the conventional account of the evolution of terrestrial life forms and wondered if, despite the generations of painstaking effort and research that had been devoted to the subject, there might after all be more to the story than had up until then been so confidently supposed. Several thousands of millions of years was a long time by anybody’s standards; was it so totally inconceivable that somewhere in all those gulfs of uncertainty, there could be enough room to lose an advanced line of human descent which had
