The full story is available here as part of the "Return to 'Return to Oz'" and other tales anthology.
Footprints on the Lakeside
A long, long time ago, before man began to measure the passage of time, Kal lived in a small cave by the side of a lake. Kal was old, he had survived fourteen summers of his life, and that made him one of the strongest amongst his tribe.
In these days, when the sky was still red for most of the day and the sun was larger than it is today, Kal would spend most of his days hunting on the great veldt for food to bring back to his people. Most of the males in the tribe who were not too young or too old would join him, but Kal was by far the strongest amongst them, for he could wrestle any of the thickly-haired gazelles to the ground without hurting himself. And when the sharp-toothed creatures that stalked in the night came to the caves to feed, Kal would fight them off with his sharpened sticks and cutting stones. Kal wore the skin of one of the night creatures to conceal his nakedness, and lined the floor of his caves with other pelts to keep him warm at night.
It was the day after the old one had died. Kal had no language, and did not have a name for the word ‘father’, but he did understand that the old one was important to him in some strange and indistinct way, and had done his best to ensure that this old one was fed before the other elders of the tribe. The old one had perished slowly, having been bitten by a creature that would one day be recognised as a snake, but its teeth had been sharp and edged with a poison that had steadily infected the old one until his ankle had swollen and left him unable to walk.
Kal had seen others die before, falling to the teeth of those that stalked the night, but he found himself uncertain what to do now that the old one had died. The sun was dipping low in the sky when Kal decided what he should do for the old one. Taking great care, Kal gathered one of the skins of a night creature that he had slain from the floor of his cave, and wrapped it around the old one’s body. Then, carefully, he lifted the body and walked down from the hillside towards the lake.
The lake sat at the foot of the hill, with a small trail of shale stones that lead down to it from the caves. Kal stepped cautiously, knowing that if he hurried too quickly the stones of the trail to the lake would cut his bare feet. The lake itself was a thing of curiosity to the tribe, for it was the source of the water that they drank each day. There was no other water for many days walk, and so the tribe had lived here by this lake for years beyond memory. Kal kneeled down next to the lakeside, and placed the old one’s body beside the water. Looking out into the lake, Kal watched as its surface shimmered slightly in the red sunlight, the waters looking to be a hot orange-red hue. At times, the water seemed to sway and move slightly, almost as if on its own volition.