"You're leaving me behind, I'm afraid," Mrs. Rhodes cut in gently. The old lady smiled, making no secret of her pleasure in doing just that. It had become a kind of game. The fact was that Mrs. Rhodes, a skilled nurse, was not confused by anatomical allusions. She merely wished to abbreviate a developing lecture.
A modern city whose name they ignored obliterated a segment of the trail, but they resumed operations on the far side. Now they crossed parched savanna dotted with palms. "On this island, in historic times," Miss Concher said, "ranged the largest bird ever known: aepyornis."
"Now that sounds like a primate!"
"Its egg weighed twenty pounds, and a mature bird up to half a ton. Man wiped it out, of course."
"You don't have a very high opinion of man, do you."
"That's why I'm single." But Miss Concher smiled again, too enthusiastic over the progress of the search to be properly cynical. She knew the fauna far better than Mrs. Rhodes did, identifying by description everything from a camouflaged tree-lizard to a forest cuckoo. She also called off a solitary baobab, the tree with the grossly swollen trunk that seemed to have its roots in the air in place of branches, and related an amusing myth about its origin. She knew how to get through a thorny didierea jungle, grown up in recent generations as though to preserve the secrets of the trail.
They moved on with growing excitement, day by day, until at last the trail debouched into a secluded valley. Repeated soundings verified it: this had been the home, two million years ago, of the mysterious traveler. Today it was wilderness, with only the shy lemurs and curious birds present. Where had man's ancient tutor gone?
"If I make out the lay of the land correctly," Miss Concher said, "there should be buried caves. They may have been occupied, then."
Mrs. Rhodes shook her head, marveling anew at the spinster's talents. If she conjectured buried caves, there would be buried caves.
They drilled and drilled again, searching. On the third day the bit broke through the wall of a subterranean discontinuity. Its age fell in the correct range and the trace inside was very strong.
"Now," Miss Concher said briskly, "we dig."
It had to be by hand, since the rig was not geared for wholesale tunneling and in any event the bulldozer technique was hardly appropriate for archaeological excavation. The two women dug a long shallow trench, pausing as often as they had to in deference to sex and age and inexperience. Miss Concher's contribution was a good deal more than token; her zest drove her ruthlessly. Next day they deepened it, leaving a ramp at one end. As their trench descended into the earth they hauled loads of loam, sand and gravel out in a wheeled sample cart never intended for such crude maneuver-ings.
The work was slow, their muscles sore, and both had ugly blisters on their hands despite the heavy gloves. Each day the excavation sank deeper, and their anticipation grew. Down there, perhaps, was tangible evidence of a two-million-year old culture—a culture to which man probably owed his present eminence. Blisters were beneath consideration, with the solution to such a mystery so near.
At last they struck the rocky outer wall of the cave. The drill-hole penetrated a yard of crumbling stone.
"Either we can keep digging until we come across the natural entrance," Mrs. Rhodes said, touching the aperture with weary fingers, "or we can break out the sledgehammer. I'm not at all sure my resources will survive either course."
"Hammer and chisel will do it," Miss Concher said, declining to ride with the proffered excuse though she could have done so with grace. Mere stone would not halt her. She demonstrated, flaking off wedges skillfully. "Variation of a technique used in the Oldowan industry for a million years or so, so it will do for us. The stone age had a lot to recommend it."
So the old lady knew how to chip stone! The process was slow, but it did promise to get the job done with a minimum of damage to whatever might be in the cave.
They took turns, the sighted woman laboring clumsily much of the day, and the blind one continuing far into the night. Miss Concher seemed indefatigable and she needed no illumination. Mrs. Rhodes, weary to the marrow, became too dull to marvel further at the resources of her companion. Most women of that age would be crocheting harmlessly in rockers while their grandchildren matured. Purpose animated Miss Concher, provided the motive power—but what would happen once the mission was done? Would there then be a disastrous reckoning?
But she knew the answer to that. Miss Concher would not collapse; she would find another mission, another trail to follow. In fact it was not the trail that gave her purpose, it was her purpose that revealed the trail, where no one else had thought to look. It was, as the saying went, an education merely to know her.
And perhaps within this buried cave lay the answer to the start of that purpose. Not only to this immediate trek, but to the inherent motivation of man. The thing that had given a minor hominid the bug for knowledge, two million years ago, and thrust him mercilessly into greatness. The quality that really made Miss Concher the avid scientist she was, and set her species apart from all others. Intellectual motivation.
Mrs. Rhodes felt nervous goose-pimples rise along her arms despite the heat as the breakthrough point approached. The hole was widening, but Miss Concher refused to risk damaging the interior by rushing. Something was down there, though. Broken pieces where the bit had struck? Bones? Pottery? Weapons? Books? Or something more sinister?
She slept at last to the tap-tap of Miss Concher's patient excavation, not attempting to keep up with the woman's nocturnal energy. It would have been useless to urge her to stop, to rest, to sleep, for Miss Concher lived for this discovery. Better to be ready herself, in case the strain brought serious complications.
In indeterminate darkness she woke momentarily, still hearing the tap-tap. Regardless of the outcome of this quest, she knew what she was going to do after it was over. She had already learned enough about the heritage of her species to accept some things she had denied before. She had a better marriage than she had supposed, and it was not too late....
In the morning she discovered that Miss Concher had never returned to the truck to sleep. All was silent.
She scrambled up in alarm and ran for the gaping trench. She should have stayed up, kept watch... if the grand old lady had hurt herself, or collapsed, or—
She need not have worried. Miss Concher was standing waist-deep in the cave excavation, lifting out objects and using the main trench as a display shelf. Meticulously arranged were a series of irregular objects and portions of an animal skeleton.
"Miss Concher! Have you been up all night?" But the question was gratuitous and rhetorical.
The woman lifted her white head, smiling tiredly. "Yes, we have found the answer. We know who started man on his way. The artifacts are conclusive." She caressed the dirt-encrusted object in her hand. "Mesolithic culture, I would say—shaped tools, but no gardening. They were obviously able to sail on the rivers and ocean, at least with some kind of raft, and to domesticate certain animals—"
"You know who trained Australopithecus to—"
"Yes, the hominids were one of their domestics. They recognized in Australopithecus the potential for really effective service, and they took the long view. A few thousand years of selection and training—more than enough to affect the species profoundly—and man was on his way. He even—"
Mrs. Rhodes was shocked. "You mean man started out as—as a pet, like a dog?"