She hadn't even wanted to go to the party. 

She hated those kinds of parties. 

She didn't know it would turn into this.

She had gone to the washroom to hide out until her friend was ready to leave. 

She hadn't known there was someone else in the washroom.

She had just sat down on the toilet that was opposed the mirror. 

She pulled out her phone to check her instagram, when she noticed something odd in the mirror, so she got up to take a closer look. 

She looked at her reflection for a few seconds, noting that her hair looked a bit longer than she thought it was, before going back to her phone. 

A few seconds passed, but then she looked back to the mirror, and her mouth dropped open in shock. She didn't have blond hair.

That wasn't her in the mirror.

Whatever was in the mirror smiled at her.

Later, someone would go into the washroom, and find a blond girl sitting on the toilet.