Cerberus. In the school. Kept behind a door accessible with an Unlocking Charm.
Jo was certain what she had overheard, she had heard right; because as she stood dumbstruck behind the suit of armour just outside the doors to the Great Hall with the intention to surprise Hermione and Neville, the recent revelation meant many things.
Many, many things.
If the door was still left unlocked, it was a problem.
And if wasn't? She needed to know it was enchanted with an Anti-Alohomora Charm this time.
Despite the brief niggling sense of betrayal, Jo fully understood why the two had ultimately kept it from her. The sheer possibilities racing in her mind made her so jittery she could increasingly feel the intense throbbing of her pulse in her fingertips spread to her sternum and neck and how it rushed in her ears.
Because if there still wasn't an Anti-Alohomora Charm, it meant something was wrong.
Incredibly wrong.
And that sense of wrongness swooped so violently in her belly even Hogwarts's resplendent magic struggled to guide her back to her dorm room without any witnesses.
Yes. Hogwarts is sentient.
(also it's still Saturday in the fic)