On her way to the Huffie common room Sarah walked passed the hourglasses.
Glancing as she did so to check they were still within sight of Ravenclaw.She was going to keep walking until she realised something.Doing a double take,Sarah stood with her mouth wide open,staring at the place so many gleaming stones had been the previous day.
"Wha-- wha--..." was all she could say.
It was empty.Nothing to be seen except....emptyness.

Stunned into silence,Sarah watched as Professor Shackleton stormed off into the distance.
All she knew was that she didn't want to be the person on the end of her Head of House's anger.