Harry Potter liked walking Hogwarts halls, even when it was quiet as a tomb. Perhaps especially then.
It was nice, in its own way, to enjoy the receptiveness of the place. On this night, he hadn't asked himself to go anywhere special, so he was surprised to hear voices, as he approached a cross-corridor.
Snape... and Quirrel?
Harry Potter remembered what he'd done at the Dursleys, finding a place with good echoes, not confusing ones*.
"Just what exactly do you think you're doing?" Snape hissed.
"I think it's smarter for you to think of what you're doing, and where your loyalties lie." Quirrel said snidely. Loyalties... divided.
"You'll rue the day you reached for glory," Snape snarled. From personal experience?
"And you'll rue the day you turned your coat, Renegade." Quirrel responded. Renegade wasn't a term for a turncoat. It was a term for someone without allegiance, who'd turned his coat so many times you couldn't figure out which way was supposed to be out anymore.
Harry was quite glad that they strolled away. And then he abruptly realized that Quirrel hadn't stuttered at all during the exchange. Was Quirrel just pretending to be a scared little duckling?
Harry's feet led him back like lead. He moved slowly, not putting too much emphasis on any of the points he'd learned.
There was a bright side to all of this: It was nearly certainly a Hogwarts teacher who had done this.
Harry nodded, and turned for bed. In the morning, he had a will to write.
*There is an entire field of study that designs acoustical structures like auditoriums. You want bouncy walls for music, and deadening walls for speeches.
[a/n: I hope i've made it sufficiently ambiguous that it makes sense that Harry would at least consider Snape as a suspect. Leave reviews!]