The next day
Lucy was headed for the Gryffindor dormitories when she noticed the large number of students gathering at the entrance to the said dormitories. Lucy pushed through the crowd to see the Fat Lady's portrait torn, as if by claw marks, and no sign of the Fat Lady. All the other portraits in view were in various states of distress. Crying, yelling, ect.
"Headmaster is here. Move." Someone ordered as Dumbledore made his way through the crowd to have his eyes take in what Lucy had just seen.
"Mr. Filch. Round up the ghosts. Tell them to search every painting in the castle. Find the Fat Lady." Dumbledore commanded, but there was no need. Filch had already found her.
"There's no need for ghosts. Fat Lady is there." Filch pointed, causing the gathered and gathering students to shove their way to the portrait of what appeared to be to be an African wild scene.
"Who did this to you?" Dumbledore asked the Fat Lady who was cowering behind a rhino.
"Eyes like the devil, he's got, and a soul dark as his name. It's him headmaster, the one they all talk about. He's here, somewhere in the castle. It's Sirius Black!" Fat Lady whimpered.
Dumbledore ordered all the Gryffindors to the Great Hall. In the rush to follow Dumbledore's command, no one noticed the one student who didn't, the one that slipped away after Severus Snape.