What dark stories or plots have you seen?

In order to understand human beings, an alien entered the human prosthesis ("Avatar", I had this idea 0/5 years ago) and fell in love with a human girl without any accident. He wanted to take the girl back to his planet, but his companion stopped him, saying, you should remember the human body in our museum, if you don't want her to become like this ... The alien had no choice but to say goodbye to the girl and left in a flying saucer (the girl didn't know he was an alien). He heard the secret on a flying saucer. He turned out to be a human four hundred years ago, dissected and put in an alien prosthesis. Through this research ... they tried to make human prostheses on a large scale, so as to achieve the purpose of invading mankind. ... he activated the explosive device and died. The girl happened to pass by the window and thought that the exploding UFO was a meteor, so she hoped that he would come to her soon.