Revenant Eve by Sherwood Smith
Once upon a time, I had known nothing about my family. But then I went to Europe and discovered who I really was. And my new life...well, it was like something right out of a fairy tale. I was a member of the royal family of Dobrenica, a tiny, obscure European country with some very unusual attributes. Like magic. And ghosts. And vampires.
But for the first time in my life I was truly happy. I was engaged to be married to the heir apparent to the throne, and we were in love. So my mood was high as I walked under the triumphal arch in the center of the capital city and passed the off little painting of a door that had intrigued me ever since I first came to Dobrenica.
It was rendered so realistically that on first glance it seemed three dimensional, and I always ran my fingers over the amazing painting as I passed. But this time, my fingers closed on an actual cold metal doorknob, and the door swung inward, revealing a sun-drenched landscape and a teenage girl with honey-colored braids.
As I stepped over the magical threshold, she spoke.
"You are called to guide the child Aurelie,"she said. "But that is only half your task: to save Dobrenica, you must bring her here."
And with that, she disappeared, leaving me floating like a spirit in a strange world, two hundred years in the past.