Donald Moffitt - Genesis 02

get back. Let’s get going. We’re wasting our air supply on the outskirts.”
    “As long as we’re here, let’s just take a look, ” she said.
    “All right.”
    He gave in and followed her down the slope. He didn’t like it. They were in a deep groove, cut off from sight of the walker and the never-ending landscape. Only the stars burned overhead.
    Ame was unconcerned. She played the light of her torch along the join of the two surfaces. Color vision returned, showing Bram vitreous streaks of green, brown, and yellow mixed with the gray. Even to the naked eye it was apparent that the rubble had slid down the slope to cover any possible cracks to a depth of many feet. It would take a lot of work to clear it away.
    But he was wrong. Ame’s torch played on a gaping black aperture that ran down the rocky crease in a spot that seemed remarkably free of rubble. In fact, the rubble seemed to be piled higher on either side of it.
    “It goes all the way down,” she said. “About twenty feet to where the floor is. Big enough to squeeze through, and then there’s a sort of triangular tunnel made by the edge of the roof slab and the angle of the floor and wall. The tunnel’s clean—hardly any debris to clear away. I wouldn’t have expected that. The roof must have collapsed with miraculous precision. Half our work’s been done for us already. And when we explore the whole length of the cleft, we’re bound to find places where we can get through into the main part of the ruin.” Her voice rose with excitement. “Acres and acres of undisturbed … anything! Bram -tsu, why don’t we just—”
    “No,” he said firmly. “We’re not going to go crawling in there now. For one thing, we’d be out of radio contact. Come on, Ame. We’ve seen everything there is to see for the moment.
    “I suppose you’re right,” she sighed. She played the beam of her torch in widening spirals around the entrance. “But I don’t understand where all the rubble went.”
    Then they saw the footprints.
    The tracks converged on the hole from all directions. Heavy traffic. The reason they weren’t obvious in the immediate vicinity of the hole was that they became too thick there, obliterating outlines and churning up the dust.
    Besides, getting in and out of the hole meant belly crawling, further erasing any tracks.
    But they were very plain farther away.
    They were longer and narrower than an ordinary human footprint, but they covered about the same area and presumably would have supported a body of similar weight. The foot that had made the imprint had been encased in a tubelike boot with a ridged underside.
    When he was able to catch his breath he said, “How long ago?”
    Even his untrained eye could see that the outlines of the footprints were not as sharp as the prints he and Ame had left.
    Ame produced a tiny measuring stick and compared the depth of the two sets of prints. Then she poked the rod into the dust in several places.
    “They’re recent,” she said.
    That startled him. “How recent?”
    Her features worked within the helmet. “We’ll have to assume that the dustfall on this world has been diminishing during the last seventy million years, as the disks swept out their orbit. Dimishing on a logarithmic scale, maybe. Most of the dustfall must have taken place in the first few million years. But the roof must have collapsed, too, within a few million years of the time when Original Man abandoned the place, because of the later buildup that replaced the dust that slid down into the crevice.”
    “Ame— how recent?”
    “It could have been within the last thirty million years.”
    Bram swayed in the low gravity. “More than forty million years after we thought the human race died out,” he whispered. He grasped her space-suited arm. “Could these prints have been made by a human foot?”
    She shrugged. “Depends on what you want to consider human. It took the human foot only a few million years to evolve from a grasping organ that looked something like our hands. I suppose that in another forty million years, it could have evolved into something that looked like that. ”
    She splashed her light around the prints. “It’s hard to tell what might have been inside that boot,” she said finally. “But the elongated proportions aside, that could be a foot with the normal configuration of heel, instep, and toes. They always bend in the same place, so they had bones. Not like a Nar footprint that