A once-burly but now emaciated man trembled down a stone path atop a mountain, surrounded on either side by bowing tribesmen. Their heads, impossibly elongated, ended in a dull point. Every inch of their abnormal heads were decorated with tattoos of animals, gods, symbols...
The man stumbled as he walked. He could feel the tribesmen's eyes on him, despite the fact that their heads all faced down as they bowed graciously to him. A gigantic metallic craft suddenly came into sight only feet before him, seemingly materializing from thin air.
The tribesmen sat up to their knees and began a primitive chant, with their arms raised into the air and their hands shaking rhythmically. It was a ritual. The man fell to his own knees before the craft. His eyes explored the surface: the object was very clearly futuristic. It was shaped like a flattened semi-triangle with a round disc attached to the bottom, curving upwards at the edges. The edges themselves carried the very same symbols that were tattooed onto the heads of the tribesmen.
A passage opened in the lower section of the craft, blasting out a gust of unbelievably fresh air. While the tribesmen still hollered and screamed in their native tongue, noisy clanking sounds came from the inside of the craft. Footsteps.
Out of the passage came a truly alien beast. Its stature was at least eight feet, and its flesh was like nothing that had ever been seen on Earth: fleshy and soft, but with the texture and appearance of very fine reptilian scales. Its body was jet black, save for its head, which had a white patch at the very tip of its extended skull. The alien's eyes stretched backwards with its skull, taking on a hazy red coloration, like diluted blood.
The man was unable to react as the divine thing stepped towards him and placed its wiry hand upon his head, and visions flashed into his mind.
Planet Earth. No civilization. Pristine forests covered the world, and mankind existed in only a few scattered pockets of primitive monkeys, still covered in scruffy fur and with pudgy faces and partial-snouts.
A satellite-like object orbited the planet, humongous, silver, and round... approximately the size of the Moon, but lacking its rocky surface. Coincidentally, no moon was present around the Earth. A single sleek pod shot from a gate in the bottom of the satellite and blazed through Earth's atmosphere, completely immune to the intense friction that would obliterate any other object of its size.
It crashed down in a remote forested area, and the monkey-like ancestors of mankind gathered around in savage curiosity. Out of the pod came two beings -- identical to the one which the man encountered just now -- and entrapped two primates, one male and one female, and returned to the satellite.
Thousands of years pass. Two new species, a hybrid of the monkeys and the alien beings, now existed on Earth: a flat-faced, lean, quick species which was unskilled with tools but had mastered fire; and a bulkier, slower race with an overshadowing forehead, who were the masters of the tools. The lean ones a breed between a female primate and a male being, and the bulky ones a breed between a male primate and female being.
They watched from afar as the leaner of the two slowly murdered an entire species, and entire culture. There was no doubt that these beasts, savage and resilient, were the ones necessary for their ultimate purpose.
A shining material was extracted from the ground by one being, who was disgusted at merely making contact with the soil, and it held the object before the dumb creatures who wore coverings made from the hides of other wild beasts.
Short years pass, and the whole species has become obsessed with mining the glistening, worthless material from the Earth itself. It came in high quantities, but by the time the beings had had their fill, the planet was nearly drained of the gold. The beings had enough gold to hyperheat into a gaseous state to replenish their gold-dependent atmosphere.
The species continues to grow, and the beings hadn't yet finished with them. There was much left to do with their creation, so much.
The desert became filled with hardy inhabitants who were obsessed with erecting enormous pyramids and obelisks, inscripted with symbols representing their gods, these beings. A king, rumored to be part god and part man, ruled over the dry colony until his untimely death.
Farther west, in a thick and ever-thickening jungle, a nearly identical civilization in the mountains constructed their own pyramids, as instructed by the beings. Viewed from above each and every one of these triangular structures, worldwide, aligned to a single grid which covers the Earth, a grid which is naturally imbued with electrical energy from the planet's magnetic core. The structures channeled this energy into the air, for easy collection by the beings' vessels to refuel.
The tribes began to worship the beings as gods, honoring them by extending their own craniums with wooden planks tied around their heads from birth to more closely resemble them, without instruction from the beings.
They were done with mankind, he realized. Mankind had fulfilled its purpose centuries ago, and was now utterly worthless in the eyes of the beings. This was the beginning of the end for mankind, and he had been the first to learn why. The tribesmen accepted their fate, remaining silently and motionlessly bowed before the alien craft.
This was the end of the human race, and the entire planet itself.