Five years later:

"A prophecy," Severus Snape repeated numbly. "So that was why the Dark Lord sought them."

"And why your timely warning sent me to Lily and James that day. To whisk them into hiding."

"For all the good it did," Severus said, keeping his voice dry. Old pains no longer had the power to harm him. Or so he thought, until Dumbledore's next words.

"I knew the moment you told me Voldemort sought the Potters that your son was in danger."

Snape's heart seemed to stop in his chest. "What?"

Dumbledore steepled his fingers and gazed at him kindly. "No pretence now, Severus. I had hoped you would come to me before now about this matter."

"There is no matter," Snape said, pushing himself out of the too-soft armchair. Around the room former headmasters and mistresses stared down at him, eyes curious. He had always hated Dumbledore's study for all those insolent eyes.

"I've given you five years," Dumbledore continued relentlessly. "Five years to heal and build a life for yourself. But events move at a pace and here you are, still rootless, still wrapped in your self imposed exile."

"How dare you," Snape breathed, wrapping his dignity around him like a cloak. "Our former relationship as master and spy does not give you the right to lecture me about my life!"

"How about my role as your son's keeper?"

"Don't call him my son!" Snape almost screamed, then caught himself, biting his lip to keep the rest of the angry vitriol contained. "Do not call him my son," he whispered harshly.

"Do you deny that he was born of your seed?"

Snape shook his head, not at the words but at the memory they invoked. Lily, eyes wide, hand outstretched. James, sunburned and laconic, leaning against the door jamb in his lanky way, eyes shaded. What it must have cost him, begging for his hated cousin's seed.

"I do not deny that I granted them that favour," Snape managed to force out between clenched teeth.

"Perhaps one day you will tell me why," Dumbledore said softly. "But for now I must call young Harry your son, because that is all he is. You are all he has left."

"Then he has nothing," Snape said starkly. "I told them as I tell you. I want no child, I need no child. Once the spell was performed my part was over. I cared never to see any of them again in my life."

"When James and Lily were killed I understood why you could not come to me and enquire after the boy's safety. But surely now the truth is out between us you can ask. You can ask me about Harry."

"I don't care about Harry," Snape said, pushing that honesty between them to vie with the truth the old wizard seemed to set such store by. He turned on his heel, wanting to shake the dust of this hated old castle off his feet. He had few good memories of this place.

"He's with Muggles," Dumbledore said baldly and against his will Snape froze in his tracks. "Lily had a sister, you see. Married a Muggle and settled down to Muggle life."

"Muggles," Snape repeated, trying to come to terms with that. Then he frowned and shrugged irritably. "Well, so what?" he threw back over his shoulder. "It's not my concern."

"If not your concern then whose?" Dumbledore said at his side and Snape spun, holding one hand to his pounding heart. He'd always hated the way the old wizard could do that.

"I don't take orders from you or anyone any more," Snape reminded him. 

"Order?" Dumbledore said, white brows raised in comical surprise. "Dear me, no. As if I would order you! This is more a request. A favour, if you will."

"A favour?" Snape repeated suspiciously. As well he might.

"A small one," Dumbledore said swiftly. "Tiny. Miniscule in fact."

Snape snorted impatiently. "Do I owe you a favour?"

"You've always struck me as an honourable man, Severus. In your own way." Dumbledore wandered the room, slipping his hand in a pocket and pulling out something he fed to his absurdly coloured bird. "What do you think?"

Snape shifted his feet a little uncomfortably. Unfortunately he knew he owed Dumbledore very many favours. It just wasn't like the old crackpot to remind him so pointedly.

"What is this favour then?" Snape finally said grudgingly.

"The boy is in safe hiding, ancient magic protecting him while the place he calls home is with his mother's kin." A sharp gaze held Snape in place. "You know the power of that kind of blood."

Snape nodded curtly, hating that he felt like a sullen teenager again, called to answer for some foolish prank in this ridiculous office.

"I have no such protection, and I am watched fairly constantly. You however are free to roam, and, if you don't mind my saying so, no one really cares where you go."

"I have worked very hard to make it so," Snape bit back, then cursed at letting himself be baited.

Dumbledore was smiling genially, probably happy now he'd goaded yet another response out of him. Honestly, Snape thought, the old bastard was practically Slytherinish at times.

"Can you get to the point?" Snape ground out.

"I've had disturbing reports from those who watch him. The Muggles' treatment of him deteriorates as he ages. The last report was serious enough to worry me."

"Treatment?" Snape repeated, curious despite himself. "Did you not say he was being raised by this... family."

"I had hoped he would find a family there," Dumbledore said carefully, eyes averted. Snape frowned, finding this more worrying than any words. What had this old fool done, that he would not even look him in the eyes?

"But he has not?"

Dumbledore sighed and shrugged, gaze now on his long fingers, stroking over the ancient green leather top of his desk. "You understand why I need you to go, see these people, this home. Ensure the boy is well treated."

Instinctive denial rose up in him. See the boy? That was the last thing he wanted.

"Surely someone else can be trusted?" he began, but the headmaster was shaking his head.

"Only two others know his whereabouts, Hagrid and Professor McGonagall."

Snape pursed his thin lips. Hagrid he could understand, the huge oaf would attract too much attention. "Why not McGonagall then?"

"Professor McGonagall," Dumbledore corrected him pointedly, as if he were still an insolent first year. "I'm afraid Minerva is slightly... biased on the subject. She never wanted me to leave him with the Muggles in the first place."

"Perhaps you should have listened," Snape muttered.

"It has to be someone I trust implicitly with his safety," Dumbledore said carefully. "As you know all too well, former Death Eaters roam with impunity..."

Another hit, this one drawing blood. Another subtle reminder of what he owed, and to whom.

"And after all," Dumbledore continued, fiddling with his pen and ink stand now. "The boy means nothing to you, as you've said. What harm can there be in checking up on him?"

"Indeed," Snape agreed. He looked out a nearby window at the softly falling snow. "Right now?" he asked dryly. "On Christmas Eve?"

Ingenuous eyes widened. "I'm sorry. Did you have plans?"

"As well if I had," Snape muttered. He guessed the master manipulator's trick. Look in on a cosy little family, albeit a Muggle one. Become overwhelmed with longing for such domestic splendours and whisk the child away to build his own little nest some where.

Pathetic.

Dumbledore was approaching, wand in hand. "I need to put the location in your head." He raised the wand and smiled. "And Severus? Merry Christmas."