She's a Loveable Mystery (Harry PotterxOC)

Dumbledore needed some one for a mission. A mission to keep an eye on Harry Potter as he starts his fifth year at Hogwarts. Who better to ask then his own goddaughter? Arianna Carter. Arianna jumps at the opportunity to do something as a war is growing in the dark. She travels from her home in America to do her part but wasn't expecting to fall for the Potter boy. Who knew it would be so hard to contain your feelings for someone who doesn't even know who you are? After all, she is undercover. But what is she undercover as? Well, you'll have to read to find that out.

I do not own the characters or the central plot of the story. They are from the incredible J.K. Rowling. I only own the Arianna, her parents, and Ezra.

This story starts in Order of the Phoenix (the movie).