"I saw you and Snape in the forest--" [Harry] blurted out.

"Yes," said Quirrell idly, walking around the mirror to look at the back. "He was on to me by that time, trying to find out how far I'd got. He suspected me all along. Tried to frighten me - as though he could, when I had Lord Voldemort on my side..."

-- Harry and Quirrell, Chp. 17, Harry Potter and the Philosopher's Stone

Snape glided smoothly out of the castle and headed for the Forbidden Forest. He'd had one of the house-elves take Quirrell a note, asking to meet him out there. It was better by far that they didn't have this confrontation in the school itself, if only to avoid being overheard by any students. The fact that everyone else was at dinner at the moment was an added precaution.

It didn't take him long to arrive at the clearing he'd specified in the note. Quirrell was standing over by the far end, looking more nervous than ever.

Snape sneered, not fooled in the slightest. Oh, at first he'd thought Quirrell had just gotten worse over the summer, but ever since the Slytherin/Gryffindor Quidditch match, he'd known better.

"Quirrell," he said coolly, stepping out into the clearing.

"S-Severus," the DADA professor replied. That stutter could get extremely irritating. "What d-did you want t-to t-talk about?"

"A number of things," Snape answered. "The third floor corridor, and three-headed dogs, for instance."

Quirrell's expression flickered. It was just for a moment, but it was enough to let Snape know that he'd hit a nerve. It was also enough to confirm that either Quirrell had changed a great deal, or he'd found an excellent acting coach over the summer, because a moment was all it lasted.

"And Mr. Potter," he added, letting his tone get colder.

Quirrell blinked. "Interesting t-topics. B-but I d-don't know why you wanted t-t-to meet here of all p-places, Severus..."

Snape's voice was icy as he replied, "Oh, I thought we'd keep this private. Students aren't supposed to know about the Philosopher's Stone, after all."

"S-surely you c-c-can't think that I--" Quirrell mumbled.

Snape sneered at him, making it clear that he knew perfectly well that Quirrell was after it. Then he interrupted, hoping to catch the other man at least a bit off-guard, "Have you found out how to get past that beast of Hagrid's yet?"

He hadn't, Snape noticed, with a certain amount of relief. Whatever had happened over the summer might have taught Quirrell how to mask his expressions, but he wasn't quite good enough at it yet to fool Snape.

"B-b-but Severus, I--"

Time to see if intimidation would still work. Taking a step toward Quirrell, letting his height help with looming over the other man, Snape said, "You don't want me as your enemy, Quirrell."

"I-I don't know what you--"

"You know perfectly well what I mean," Snape replied coldly. Perhaps if he gave a little added incentive... "Remember the first Quidditch match, Quirrell? I'm sure that you'd prefer that Dumbledore never heard about your little bit of hocus pocus." He gave Quirrell a pointed look. "I'm waiting."

Quirrell tried to look puzzled, but didn't quite succeed. There was something in his eyes... "B-but I d-d-don't--"

"Very well," Snape cut in abruptly. He wasn't in the mood to listen to Quirrell deny everything and make excuses. He'd give the other man a bit of time to think about the possible consequences, and then reel him in. After all, as long as Quirrell didn't know how to get past that miserable beast, the Stone was safe enough. "We'll have another little chat soon, when you've had time to think things over and decided where your loyalties lie." And if you do make the mistake of deciding they lie with Voldemort, I will take great pleasure in turning you over to the Aurors. Especially with what you've put me through trying to protect Potter.

Pulling his cloak over his head, he turned away - which Quirrell would no doubt recognize as a sign of utter contempt, since Snape was a Slytherin, after all - and strode out of the clearing, heading back toward Hogwarts.

As he walked, Snape reviewed the conversation in his mind. Unfortunately, nothing Quirrell had said would serve as proof for Dumbledore, and he could hardly show the headmaster the subtleties of Quirrell's expressions that had spoken volumes to his eyes. Even a Pensieve wouldn't help get things across properly.

Emerging from the Forest, Snape glanced around to make sure that no one was watching, and then headed for the main entrance. He'd only gone a few steps, however, when he abruptly realized that he was rubbing his left forearm.

It had been over ten years now since the last time it had burned, but Snape still remembered the pain of the summons; and the less physical, but still very real, pain of what he'd done when he'd still believed that Voldemort was right. Even as Dumbledore's spy, he'd had to do things he had come to consider exceedingly distasteful, and he had no desire whatsoever to return to that life.

There was only one being that Quirrell could possibly be trying to get the Stone for, and that was Voldemort. And if Voldemort got hold of the Philosopher's Stone, nothing - not even whatever it was that had enabled Harry Potter to survive the Killing Curse - would be able to stop him.

Snape would do everything in his power to prevent that from happening.