A ghost nobody much liked came through the Great Hall doors toward the end of the feast, cackling strangely.
"What are you doing here, Peeves?" Filch, who was by the doors, stepped forward at once. "Today is no time for your nonsense."
"That fool of a Fat Lady had half her portrait sliced away, while you lot were happily celebrating... I thought it was very funny, so I came to let you all have a look too."
Peeves was as gleeful as ever.
"What did you say?" Dumbledore's voice carried over from the staff table.
The strange grin on Peeves's face vanished at once. In front of Dumbledore, the head of the Castle, he did not dare clown around as he usually did.
"Someone damaged the Fat Lady's portrait." Peeves's voice drifted through the air above the Great Hall. Everyone fell silent, holding their breath and listening intently.
"I saw her run bashfully into a landscape painting on the fifth floor, Headmaster, sir. She's hiding in the grass, crying her heart out."
Dumbledore's expression immediately grew grave. "Minerva, sorry for the trouble, but please go to Gryffindor Tower now and see exactly what has happened."
"Argus... sorry for the trouble, but please go to the fifth floor and find the Fat Lady."
Filch nodded solemnly, pushed open the doors, and left, with his Mrs. Norris following him.
"As for everyone else, remain in the Great Hall for now." Dumbledore looked around and waved his hand. The Great Hall instantly returned to its usual appearance, the candles hovering overhead turned their normal orange-yellow, and the bats vanished all at once.
"Peeves, did she say who did it?" Dumbledore asked quietly.
"Oh, she did." Peeves stepped on his right foot with his left in midair and shot a little higher. "The Fat