Do you remember the late-1990's movie "Independence Day"? Where the aliens made no attempt to conceal their presence, but merely showed up and did what they intended to do, not caring about us humans' possible reaction?
Well, that is how they do things.
Different species of alien than in the movie, but they simply took advantage of their superior technology to do whatever they wanted -- and unlike in the movie, we couldn't find a weakness to exploit. Their ships showed up very clearly on radar as they surrounded the planet, obviously scanning us, for three full days. Then they sent smaller ships down into the atmosphere and to the surface, systematically exterminating all high-ranking military commanders of every military force on earth, the top leaders of all terrorist groups, and the leaders and financiers of every authoritarian organization (be it a government, a church, or any other kind) on the planet. They were very careful to target ONLY the leaders, and the whole thing didn't take more than 3 minutes, as they had tens of thousands of ships swarm downwards. Nothing we tried could damage their ships. The Russians tried launching two nukes, and the nukes swerved away from the alien ships and landed right back where they started from, wiping out a Russian nuclear-launch site and contaminating the surrounding area with radiation.
After the sudden loss of many of our planet's so-called authority figures had stunned us collectively as a species, one of the alien ships flew to New York City and an alien called a press conference at UN Headquarters. Naturally, it was broadcast worldwide. He -- it was clearly a he -- spoke in English, but his speech was live-translated into other languages as he spoke, so all of humanity could hear why the things had happened.
"Good day, ladies and gentlemen -- or night, as the case may be. You may have noticed that our ships have wiped out what you call `right wing' and `authoritarian' leaders, as well as your military commanders. This is not because we believe that being left wing and progressive is better. On the contrary, in fact. Our own society is firmly authoritarian. Our king commanded us here to collect slaves with some basic intelligence, and the ability to speak. Those of you who followed your leaders who have been executed will make excellent slaves. Our ships are picking your people up now, in fact. If you blindly followed your own leaders, you are.... what is your term?... sheeple."
A tall man carrying a gun stepped up towards the dais where the alien was speaking. "I ain't no sheeple!"
The alien smiled. "Of course you are a sheeple, sir. You followed your church leader's words to a T."
The tall man pointed his gun at the alien. "Fuck you!"
The alien lifted his hands to show two rings he was wearing, a red one on his left hand and a blue one on his right hand. "Don't be a fool, sir, Put that primitive kinetic weapon back in its holster."
"You can have my gun when you pry it from my cold, dead fingers!"
A beam of blue light flashed from the blue ring, and the tall man's hand was suddenly encased in ice. The gun fell to the floor.
"Your proposal is acceptable."
Two beams of red light flashed from the red ring. One of them, a powerful one, turned the fallen gun into a melted pile of slag. The second, more gentle one removed the ice from around the tall man's hand. A blast from the blue ring froze the slag that had been a gun before the heat could cause any trouble.
"Now, where was I before I was interrupted? Oh yes. We will collect your sheeple to be used as semi-intelligent slaves. And since our king is so generous -- and we'll need to create space in our ships to house a few billion of you -- we'll give you a few billion absolutely unintelligent slaves who need no sustenance other than what they can get from the air and sunlight in return. It is easy to find unintelligent slaves, but finding ones who have some brain capacity is harder. Obviously, you cannot successfully interbreed with the slaves we will provide you, as the genetics are too different. In 15 minutes we will have completed the exchange. Are there any questions?"
A reporter from the New York Times spoke up. "So, that's it? After this, you disappear back to... wherever you came from... and we never see you guys again?"
"Correct, ma'am."
The Washington Post had another question. "Before you leave, will you pass on any secrets of your advanced technology?"
"No, sir."
And sure enough, 30 minutes later the alien ships, with about 4/5 of the remaining human population onboard, were headed out of the Solar System. True to their word, they had left behind green-skinned creatures that were vaguely humanoid in shape, but unable to speak or think for themselves. As I learned by experiment, they could obey simple commands, the key word being simple. I understood now why they wanted a class of slave with more brain power.
What was left of our world leaders quickly formed a unified, progressive government -- all the people who didn't think that way were either dead or slaves on board an alien ship, after all. However, as I cynically observed, the only reason we could be "progressive" was because we now had a vast underclass of unintelligent slaves to do all the hard labor. I guess humans are who they are.
Our sole objective was to catch up to the aliens in technology -- after all, the next encounter might be with ones who actually DID want to exterminate us all, a la Independence Day. Since I did not have useful skills to devote to that endeavor (I had been a middle manager, not a scientist), and we now had enough labor from the unintelligent slaves the aliens had given us, I had nothing to do. The concept of money was obsolete, and with so many fewer humans, there were no resource issues anymore.
Like the rest of the people who were nonscientists, I was assigned one of the new slaves to assist me in any way I wanted. Being alone and male, and still only in my 30's, what I mostly wanted was sex. And the slave assigned to me was female. Her body shape was sort of humanoid -- she had two arms, two legs, two breasts, a head, hands and feet. She didn't have fingers or toes in her natural state, but could form them if needed. She didn't have a mouth, a nose, a vagina or a rear opening in her natural state either, but she could adjust herself to create something akin to them. She didn't wear clothes -- none of the slaves we had been given did. If you disregarded the green skin, she could almost pass for a human.
Since there were no humans around, just my slave-girl (who I had decided to name "Kara"), I didn't wear clothes either. I called Kara into the room I was in, and pointed to the bed.