Roughly 150 years ago, a virus struck the earth without warning. The virus proved fatal to over 75% of the planet's population. Governments and civilization were ground to a halt, and eventually the electrical grid and modern technology stopped functioning. Surviving humans grew more nomadic, looking for supplies and defensible positions as they battled other tribes. The virus continued to deplete the human race, and it seemed that extinction was a certainty.
20 years ago, the situation changed when an alien spaceship touched down on earth. Their name was unpronounceable to the human tongue, so they were simply dubbed "the visitors." The visitors were everything humanity needed. They cured the virus, provided food and shelter to survivors, and helped organize humans into more thriving communities.
Most trust the visitors implicitly, but others find them too good to be true. Your character is one of several who sneak into one of the radioactive zones that were walled off by the visitors because of radiation damage caused by the last days of earth's large governments. But there is no radiation. Instead, their is a small community of visitors, who are using large machines to terraform the planet into something like their home world. Perhaps worse, there are humans in the settlement, being used as pleasure slaves and personal servants to the handful of visitors. They have been fitted with implants control collars to influence their behavior and force their obedience to their masters. The implants cause a growing feeling of discomfort and pain when a command is given that isn't instantly obeyed, and a feeling of addictive pleasure when one is completed.
The intruders are caught, and their leader is taken to the base commander for judgement. Rather than destroy her, the commander finds himself wondering what it would be like to keep her as his own assistant and slave.
2. Language Barrier
This one isn't quite as complex. A massive alien ship appears overhead, sending the entire world into a panic. There is a great flash of light, and roughly 1,000 humans disappear from the city below the alien vessel. Those who vanished find themselves in little glass cells, where they are examined by human looking aliens. They are each examined, and those who are compatible enough with the aliens that they could breed are taken below. The rest are offered up to the senior officers as pleasure slaves. The humans who aren't selected will be destroyed.
Your character would be one of the humans brought aboard. She has no way to speak the alien language, and can only guess what they are doing or what is expected of her when she is selected by an officer.