On a winter afternoon at Hogwarts, the sunlight was pale and feeble, like a thin layer of frosting without warmth, barely spread over the Castle's cold stone walls.
The calm before the storm was torn open by a muffled boom that seemed to come from deep within the earth.
Along the route Filch inevitably took on his patrol stood an Enhanced No. 4 Portable Swamp, sold by Fred and George in their earlier years.
With precise timing from Ron and several older Gryffindor students, it exploded.
Dark green mud, reeking strongly of rot, swallowed the entire corridor in an instant like a living thing awakened.
The thick mud churned, nearly engulfing Filch's polished leather shoes.
At that critical instant, Filch stamped his foot.
With a click, a palm-sized silver disc sprang out beneath his feet, instantly expanding into a small, stable platform that lifted him just above the swamp.
This was the Emergency Floating Platform, a standard magical device issued to the Castle caretaker by the Academic Affairs Office. It had only one function: to protect the caretaker automatically from pranks.
Although Filch had escaped falling in, he was now stranded in the middle of the swamp, with only that tiny patch beneath his feet and no way forward or back.
"Aaaaaah!"
Mr. Filch's scream was more piercing than any he had ever let out upon catching a student wandering at night.
He trembled with rage as he stared at the mess before him, which would take until the next school year to clean up.
Mrs. Norris circled the edge of the swamp, meowing.
The tremendous commotion successfully attracted two Academic Affairs Office assistants patrolling nearby.
They arrived at the scene, and at the sight of this masterpiece worthy of a place in the history of Hogwarts pranks, their faces