Rainbow Dash has always been a girl. Well, sort of. She was born a girl, but doesn't really feel like she's one. And after a late night phone call with Pinkie, she discovers that she really just might not be one. But some people are more accepting of that fact than others....

A changeling gets a very risky and clever idea.
Pretending to be an advanced magic doll left as an anonymous gift in front of Twilight Sparkle's home.
It's so audaciously stupid there is no way it's not going to work.

We all know that Twilight Sparkle went back to her own world after she defeated Sunset Shimmer. They know it too. So why is it that on their senior trip they see a girl that looks exactly like her?!