“Yes,” Snape said. He swallowed, visibly, and forced himself to continue, “though at the time, you must understand, I thought little of it. I myself don't put much stock in Divination; I was looking merely for information with which to advance my position in the Dark Lord's circle, and I happened upon the prophecy. I gave very little thought to its contents; I did not imagine that the Dark Lord would... imbue it with the significance he did. Had I known – I promise you – had I any notion that he would think – that he would come after Lily... I would never have – I would sooner have died myself.”

Snape lapsed into an uncomfortable silence and turned away from him; Harry caught a glimpse of his red-rimmed, suspiciously bright eyes in the windowpane. Groping for something, anything, to say, Harry whispered, “I believe you,” and found, in the telling, that it was true. Snape was a good actor, he knew – had to be, to have survived Voldemort and Dumbledore both, and for so long – but Harry was sure he wasn't feigning the unsteadiness of his voice or the slight trembling of his fingers. There was something a little too desperate, too haunted, in the thin frame of his shoulders.

Snape did not acknowledge him, but schooled his expression, a veneer of icy, almost inhuman calm settling over his features. Harry imagined it was the mask he donned in Voldemort's presence, and understood, more clearly than ever, how Snape had survived two decades as a spy. The man went on, as if nothing out of the ordinary had occurred, “As soon as I understood the Dark Lord's intentions, I went to the Headmaster. I confessed to him everything; I came to him a repentant Death Eater, begging redemption for myself and sanctuary for Lily.” He darted a glance at Dumbledore's portrait, which was staring unabashedly at Harry, and perhaps purposefully away from Snape.

“The Headmaster made me an offer. He would place her – all three of you – under the strongest protections known to wizardkind, secret you away where the Dark Lord could never touch you, in exchange for my allegiance and services as a double agent. He did not tell me, then, that he took the prophecy as seriously as did the Dark Lord – that he had already planned to arrange such protections for your family – and so I came away with a sense of profound indebtedness, believing that he would go to such... extraordinary lengths, at my behest.”

He looked over at Harry, a swift, sidelong glance beneath his lashes, without turning his head. “You know the plan we devised. I was to replace Horace Slughorn as Potions master, and work for the Order of the Phoenix, while maintaining my position in the Dark Lord's circle. I would answer directly to the Headmaster, for as long as was necessary – as long as the war would last.

“I returned to the Dark Lord, and reported to him a much-edited version of our conversation – I told him that the current Potions master intended to retire at the end of the year, and that the Headmaster had offered me the position. It was not particularly unexpected, at least on merit; Professor Slughorn had indeed planned to retire for some years, and I had been one of his best students. I had a few publication credits in academic journals in Britain, and one in America, at the time. The Dark Lord was greatly pleased at the prospect of placing a Death Eater so close to the Headmaster, and pressed me to accept the offer, despite my apparent reluctance.

“I began teaching very soon thereafter. I had no inclination and little natural talent for the job, but it was a small price to pay, I thought,” said Snape, mustering a half-hearted grimace. “I did not significantly interact with the rest of the Order of the Phoenix, at the time, given that many of its members still doubted me – though the Headmaster's favor did much to alleviate their – understandable – concerns. I was not privy to their workings and strategy as a whole; I only knew what was relevant to her, including that James Potter had foolishly refused the Headmaster's offer to stand as their Secret Keeper, preferring Sirius Black, instead.

“That incident, I learned much later, was not what it appeared to be. The Headmaster had no intention of becoming Secret Keeper; it would have in all likelihood forced a Death Eater attack on Hogwarts, which the school could, at the time, ill afford. Instead, he quietly approached Potter's three greatest friends, and explained to them the predicament. Each of them came with inherent liability, to be sure – Pettigrew was too weak, Black too valuable to the Order as a combatant, and Lupin too susceptible to the Dark Lord's sway over Dark creatures – but their apparent loyalty to Potter made them the most suitable candidates. Black volunteered, naturally, and Potter accepted, over the token protest of the Headmaster.

“The conclusion to that story, I believe you know. Black was suspicious of Lupin at the time; Fenrir Greyback had just made an overture to Lupin, which he declined, but which nonetheless made Black wary. He therefore turned to Pettigrew to concoct his scheme, without consulting the Headmaster – who surely would have advised against it – trusting entirely too much in his own cleverness, as he was wont to do. The Dark Lord originally approached Pettigrew merely to force him to divulge Black's location – Black had gone into hiding – and instead, upon threatening Pettigrew's life, soon discovered that Black's disappearance was a ruse – that Pettigrew was the true Secret Keeper.

“The Dark Lord had gone alone to Pettigrew; none of the Death Eaters knew what he had discovered. But he sought me out, specifically, once he had the information. You must know, Harry, that the Dark Lord knows well how to reward his followers, to buy their loyalty and gratitude. He bade me accompany him to Godric's Hollow, that I might witness the demise of my childhood tormentor.

Snape brought a hand to his face, his long fingers covering his eyes. Harry could see his throat working, and looked down at his own knees, his hands clutching them. When he raised his head, he could make out the dampness on Snape's knuckles in the firelight. The man shuddered, the breath rattling in his lungs as he inhaled, and lowered his hands.

He spoke again, very quietly. “This news brought me no joy, as you might imagine. I – with no other recourse, as I was not in a position to even contact the Order, or the Headmaster – I asked him to spare Lily. You were the only one he had to kill, according to the prophecy; your parents were relevant only as members of the Order, and, more importantly, as obstacles to your destruction. Lily should not have mattered to his plans.” Snape closed his eyes, a gesture of infinite weariness, or perhaps some emotion Harry could not name. “I – he – the Dark Lord – did not know that we had been anything more than acquaintances – schoolmates – and certainly not that she had been any sort of friend to me. I merely – you might imagine, given the animosity between myself and James Potter, the sorts of things I might have said to convince the Dark Lord that I had personal, selfish, vengeful reasons for wanting Lily alive. He was not surprised to hear them – similar things have happened to the families of Aurors and other members of the Order. He – he agreed to reward me with the beautiful wife of my greatest childhood enemy.

He turned his gaze upon Harry, eyes haunted, desperate. “You must understand that you and your father were not at all my priority. For your mother's sake – I saw that she was unfathomably happy with him – I did not truly wish him dead, and I would have had you spared, if I there were any way to manage it, but in the end, what mattered to me was that Lily was unharmed. You were nothing to me then, Harry, except perhaps the fruit of an unwelcome union and living testament to the sum of my mistakes.”

“I understand,” said Harry, because he did. Against the tally of indignities and insults – trifles, now – he had suffered at Snape's hands, against the circumstances of his parents' demise, such disregard – and so long ago – meant very little. “It was my mum you cared about,” he said, and then, in saying so, realized the missing piece of the story.

“You loved her,” he whispered, and his tone was that of wonder.