Despite Snape having his back to Harry, the boy just knew he had rolled his eyes.
"But how she has been petrified, I cannot say…" Dumbledore continued.
"Ask him!" Filch cried, pointing at Harry. "It's him that's done it! You saw what he wrote on the wall!"
"It's not true sir, I swear. I never touched Mrs Norris," Harry said.
"Rubbish!" Filch grumbled.
"Or, perhaps Potter and his friends were simply in the wrong place at the wrong time," Snape said, his eyes never leaving Filch.
"Yes, and where were you going?" McGonagall asked, looking between the three Gryffindors.
"Back to the common room," Harry offered quickly. "I'd just finished my detention with Professor Lockhart."
"He was helping me answer my fan mail," Lockhart nodded in confirmation, and Harry didn't miss the look Snape shot him.
"Innocent until proven guilty, Argus. As I understand it, Madame Sprout has a very healthy growth of Mandrakes. When matured, a portion will be made which will revive Mrs Norris," Dumbledore assured him. "In the meantime, I strongly recommend caution to all. In light of this, Professor McGonagall, might I ask you to escort your students back to their common room?"
Harry went to move after his friends, but Snape caught his arm.
"With me, Potter."
Harry just nodded, accepting his fate and standing there whilst McGonagall rounded up Ron and Hermione, and Dumbledore went to placate Filch.
"You should tell him," Hermione whispered, as she passed Harry by, glancing up at Snape. "Tell him about the voice."
Before Harry could respond, his two friends were ushered away.