LbN: Written for .Destiny's Mirror, Mirror Challenge. My take on where the scene in "The Prince's Tale" ended up.
"—mediocre, arrogant as his father, a determined rule-breaker, delighted to find himself famous, attention-seeking and impertinent—"
"You see what you expect to see, Severus," Dumbledore said. "Other teachers report that he is modest, likable and reasonably talented. Personally, I find him a most engaging child."
Severus rolled his eyes and thought, Most people would've said the same about Potter.
"Keep an eye on Quirrel, would you?"
"Indeed, Headmaster." With a sweep of his cloak, he retreated from the office. He was fuming. The nerve of Dumbledore! Thinking he knew everything about everyone! Him, Potter, Harry Potter…. Everyone was just an open book to that man.
Rounding the corner, Severus came upon two Prefects practicing spells. "No magic in the halls!" he barked, smirking as they jumped. "Ten points from Hufflepuff…apiece." He continued his patrol of the hallways as the groans of the two students reached his ears. Most of the corridors were empty, as students had gone to bed about half an hour ago. Now and then he ran into the odd Prefect, who gave him a respectful nod before walking quickly the other way, but for the most part there was silence.
As he came into one particularly quiet hall, a door stood open to his right. Had someone been in there? Panicking, Severus rushed into the room, expecting to catch some students out. No one was there, and the Mirror was unharmed.
The Mirror of Erised. It stood high and proud in the far corner of the room. Snape went over to it, and walked around it to make sure no damage had been done. Thankfully, it was alright. He checked the stone casing, but shut his eyes every time he was near the glass. It was too much, knowing what he now knew. He didn't need that blasted mirror rubbing it in his face. Once he'd made sure that the mirror was safe and unhurt, Severus shut his eyes and stopped in front of it. He kept them closed for a moment, but then, he slowly opened them.
Looking out at him from the mirror was a small boy, with strawberry blonde hair and a large nose. He grinned and waved at Severus, seemingly delighted to see him.
"I had you all wrong, didn't I?" a voice asked.
"MERLIN, Dumbledore!" Severus yelped, spinning around. "Must you always do that?"
"I'm afraid my curiosity got the better of me this time. Occlumency was the only way."
Severus scowled at Dumbledore's smirk. "Fine. You know now. I expected him to look like her."
"I think there's a little more to it than that," Dumbledore said, smile still firmly in place. "Why else would you react so harshly to a resemblance—albeit, an extreme resemblance that you could have lived without, I'm sure. No, knowing everything Harry's gone through, you expected him to come to school broken, unsure of himself, craving acceptance from everyone. In short, you expected a physical replica of Lily, with your personality. If I may say, it was not the kind of foolish fantasy I'd expect from you, Severus. You're always so…practical."
"Then what did you expect of me, Headmaster?" Severus asked with a slight sneer.
"I expected you to be practical, as you always are," Dumbledore said, sternly. "I expected you to push Harry, to challenge him, but not to alienate him."
Severus laughed. It was a quiet chuckle, but anyone hearing it would've been blown away that he could actually make a noise of mirth. "In short," he said, mimicking Dumbledore, "You expected me to be his mentor. You wanted me to go groveling at a child's feet for forgiveness for past sins, and for us to carry on as if nothing happened? You wanted me to cultivate his magic, turning him into some kind of super wizard?"
"Not exactly the way I would have phrased it, but you get the point," Dumbledore said. Then he smiled. "I suppose it was a foolish notion, for a practical wizard like me."
Severus snorted and looked back toward the mirror. The boy seemed happy, almost desperate to be with him. A cold flood of realization swept over him. "You…you wanted me to be a father-figure?"
"Don't tell me the idea never crossed your mind. To be the father that James—"
Severus took two long strides and got right into the Headmaster's face. "Don't. Play. Me. Dumbledore." His voice was shaking with anger, but quiet. "Let me make this perfectly clear. You will not use this," he indicated the mirror, knowing Dumbledore had read his mind, "against me. There are certain things I will do without question, teaching the boy being one of them. Should the time ever come where I have to resume my old post, I will go back to it gladly. But you cannot make me care for this child. I am a human being, not a pawn in your little game. You will not manipulate me like you do so many others."
Dumbledore said nothing, but nodded gravely.
"Do you question my loyalty?"
"No," Dumbledore answered seriously.
"Then leave her out of this. I've promised already to protect him. Let me find what peace I can in that."
Without another word, Snape strode from the room. As he made his way back to his chambers, he felt as if the cruelty of the world were closing in on him—tighter and more deadly than a Devil's Snare.