15. Room
Nicholas Flamel had entrusted the Sorcerer’s Stone with Albus after He-Who-Must-Not-Be-Named had fallen which meant, that because Minerva was Hogwarts staff, she was enlisted to help make the system to protect it.

Brilliant.

When she was first approached with the task and lead into the empty chamber-like room, she was at a loss as for what to conjure up but after she had passed a few first years in the Great Hall playing Wizard’s Chess, she was…inspired.

After many late nights of extensive transfiguration and enlarging work, the room she had been given to block an intruder’s path was finished.