An astronomer spots something deep in space. It's a rogue planet, floating through space, ejected from it's star. Astronomers think these are actually very common, thrown out of star systems while their planets were forming, two form near each other, and one of them gets ejected. But he does some calculations, and realizes: uh oh, it's coming this way. We have 120 years to evacuate the planet. You can't deflect a rogue planet, it's just too big. Bunkering won't help either, the collision will obliterate both planets completely. A couple things start to happen: superstitious people pray, powerful people argue, and scientists and militaries start the gargantuan task of figuring out how to leave. In space, several construction projects start happening, all of the planets governments start collaborating on an ark, as do the wealthiest individuals, mostly dictators or religious rulers. Astronomers are scanning the skies for a planet similar to their own, our Keplar telescope is doing that right now. They find a planet that they can get to in about 200 years, so they settle on it. They know nothing of it other than the chemistry of the surface and atmosphere says it's habitable and may even already have simple life on it. 200 years in space is a long time, the dictators ships get there first. The original dictator is long dead, but his successors have been successful in keeping reigns, largely by North Korea like propaganda. This has instilled a god-like status among the leader, a status that they have convinced themselves of, after all, they are flying through space, ruling a colony on the most advanced object ever built. They get to the planet and find it's a little further in evolution then they had thought. There are indigenous ape-men on it. They aren't civilized, but they have mastered fire, stone weapons, and even agriculture in some areas. The creatures are superstitious, and worship the sun and stars because they are inquisitive, but haven't created science yet. The ships decide that they should not interfere and continue on, seeing that they've already become adept at interstellar life. All, except for one. The dictator decides to land in a populated area. The apes approach curiously, the advanced technology and the arrival from the sky to them indicates the presence of a god, and the centuries of propaganda made the leader himself fully believe that he is divine. His advanced technology makes him immune to threat from the apes, and their worship of him makes them a suitable work force. He is worshipped as a great leader and living god until the others arrive. Furious that the dictator had defied the rule of not interfering with developing planets, they demand he leave, but having already landed, the ship is unable to take off again into space (it was built in space, not meant to exit a planet.) The coalition of other ships use nuclear pulse propulsion. They drop small nuclear bombs out the back and explode them to move forward (developed by the usa in the 1960s called Orion.) The coalition cleanly wipes all evidence of the dictator and his ship from the new planet using a nuclear bomb, but the legacy of the god from the stars has already been instilled in the indigenous population. This is far-fetched, but not completely unfeasible, right? Most of that technology already exists or could exist in the next 100 years if we needed it to, and there are many instances of man worshipping technology that they thought were divine. ... What if instead of 500 years in the future, this was 8000 years in the past? What if Earth wasn't the originating planet, but the destination planet? What if the dictator was named Rah, or Allah, or Iahova? What if the stone-age apes were us?