Atara Queen had always been average.
Not a genius at school and with no special ability to distinguish herself, it was her hobby that made her shine:
Pranking.

Neverthless, Pranking won't help her when a mysterious figure appears during her Fourth Year preventing Atara from having a normal year at Hogwarts.

Unfortunatly for her, normality had never been in Hogwarts vocabulary.

Disclaimer:
I don't own Harry Potter, J.K. Rowling does. I just own a bunch of crazy characters and the plot.