“If I might speak, Headmaster,” said Snape from the shadows, and Harry’s sense of foreboding increased; he was sure nothing Snape had to say was going to do him any good.
“Potter and his friends may have simply been in the wrong place at the wrong time,” he said, a slight sneer curling his mouth as though he doubted it. “But we do have a set of suspicious circumstances here. Why was he in the upstairs corridor at all? Why wasn’t he at the Halloween feast?”

Harry Potter and the Chamber of Secrets - Chapter 9 : The Writing on the Wall
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