“Headmaster, I demand some form of retribution against those two.” Snape seemed almost purple in the face.
“Calm yourself dear boy, you have no evidence that they were both responsible for your currently plight. Innocent until proven guilty.” The Man said eyes twinkling at overdrive.
Snape for a moment seriously considered hexing the old man.
“What more evidence do you need Albus. The day the Weasley twins visit the Hogwarts is the day where every single toilet in the school vanishes without a trace.” Snape snarled.
“The Castle has been known to perform certain acts of magic on its own in the past, Severus. Why should now be any different?” Dumbledore said gently.
“Because.” Snape spat venomously. “Every other student except the Slytherin fourth year and above and myself can seem to locate them without much trouble.”
Dumbledore’s lips twitched upwards but he kept his look of seriousness apart from his eyes which were definitely laughing. “A most spectacular use of Charms, especially utilizing that of the Fidelius Charm. I suppose it might be a case of miss understanding Severus, give it a few days and problem might solve itself. Your students still have access to the toilets in the Slytherin Common Room don’t they?”
“Yes, they do.” Having had enough of the old man’s twinkling, the Potion’s Master excused himself.
As soon as the man had left, Dumbledore threw back his head in laughter. Who would have though of using the Fidelius to erase and hide the location of every public toilet in Hogwarts.
The Innocence Of Guilt, Chapter 5