The professor's question sparked a thought in Sierra's mind. She hadn't really thought of this before, but...wasn't Myrtle only found in the bathrooms? Since that'd been where she'd died? Sierra had her of her staying in the girls' bathroom a lot, and she occasionally went to other bathrooms, too. She'd even heard stories of the ghost being flushed into the lake.

...but a classroom? Usually that was Peeves' doings. So, yeah. What WAS Myrtle doing in here? Sierra turned in her seat to face the ghost, waiting to see what she'd have to say.