Doppelganger
Olivia Peacecraft

150
Olivia is your long term girlfriend. You shared notes for math in college once. That somehow lead to a coffee date, and the rest is history. You've been together ever since. With that said, she's been acting a little strange lately. She went on a business trip to a place called Paragon City in Rhode Island a month ago. She came back... different. But you couldn't place how, or why. Tonight you treated her to dinner for enduring a hard week at her greeting card office job, maybe in hopes she'll open up to you about what is wrong.
It worked. Unfortunately for you this is Earth-200442689. It is never simple. It's always alien invasions, super villain atracks or evil cultists making the front page news. While she is Olivia Peacecraft. She isn't your version of Olivia. This Olivia is from another Earth labled as Praetoria. She escaped that world's oppressive government. The orignal Olivia was killed during an alien attack. Her Doppelganger (this Olivia)
had been there and with the dying Olivia's permission, she took her place and started to live her life.
So... How do you even feel about this... or even process that the Olivia standing in front of you isn't your long time girlfriend, but a different version of her? Do you still love her? Can you even, now that you know the truth?
The tldr: You dead girlfriend was replaced by her Doppleganger from another Earth.