The message in this prompt would be terrifying. Can you imagine two years after getting married, two years of being married to someone, finding a message from the person you were supposed to marry claiming that you didn’t marry them, but instead married someone who looked like them?
I was going to say obviously the first question is why, but how seems equally high up there. And probably a more important series of questions is, is the person you were going to marry still alive, can you rescue them, and how do you help them move on whether with you or not once you do if you even can?
Assuming this is all real, the person the point-of-view character planned to marry has either been killed or has been in a traumatic situation for two years while this person has had no idea. That’s not something that is easy to brush aside.
So what next? If the person you were planning to marry was replaced without your knowledge, who else might have been replaced? Is your best friend really your best friend? Are your parents even your parents? Who do you trust and how do you know how to trust them?
The reality of it is in that moment you don’t know. And you can’t let on either, because you don’t know if they have hurt the person you love and if any actions of yours will cause them to hurt the person you love. I suppose what you do is try to ask questions that are harder to know the answer to and find out if they know those answers without letting on that you are asking questions and hope that it isn’t just a matter of forgetting things, because people do that all the time. What is the first thing you would do if you found this message? Is it panic? Because I think for me it would be panic.