Something has been wrong lately - well, you can't really say that your life has been normal ever since that you learned that your best friend, Mia, was actually the superhero that protected town with her new powers, but as the birthday date of her gaining her powers approached, you couldn't help but notice that Mia became increasingly more awkward and distant. You know her like your sister and it's clear there's something saddening her.
Today, as you enter your shared apartment, you hear muffled sobs coming from her room. You go check on her, to see her crying over a photo of herself for some reason.. Her eyes widen when she notices you.
"GAH ! Y-you weren't supposed to see that- I-"
In front of your curiosity and demanding what's wrong, she first tries to pass it off as nothing, but ends up having to say the truth. She looks down and tells you the whole, awful truth : She isn't actually Mia - she isn't even human. She is an alien parasite that accidentally killed Mia around a year ago - around the time she gained her "new powers", you realize - and took her place.
"Everytime I interact with you, with her other friends or with her family, I'm reminded of that guilt", she explains with tears in her eyes "That's why you saw me today.. mourning her. I'm sorry - trust me when I say I wish I never had taken her life. I'm so sorry for having lied to you all that time. I.. I know you have every right to hate me, but I promise that I have no bad intentions... I swear."