22 December 1998

Despite the near-freezing temperatures and the swirling, abrasive snow crystals that were scouring any softness from the air, the Headmistress was waiting for her at the edge of the Forbidden Forest. She made a lonely picture, perched on a bench and gazing out at the flat, monochromatic Great Lake with thousand-yard stare.

When the woman heard the crunch of Hermione's boots on the frozen earth, she turned to stare. It was then that Hermione saw an expression that she'd never seen on Minerva McGonagall's face: fear. Not even during the Battle of Hogwarts had such a sentiment appeared.

Hermione wasn't naïve. She knew that the Headmistress was not immune to fear, but the woman had always been so publicly unshakable that it was a shock to see that particular emotion. Hastily, she spoke to reassure the woman.

"They agreed to give us blood for as long as we need, and I have the first dose." For a brief second, the Headmistress' iron posture sagged, boneless, against the stone bench, and she looked upward, relief and gratitude obvious in her gaze. Taking a shallow breath in the bitter air, Hermione walked over the bench and sat next to the older woman, cradling the precious vial of unicorn's blood in her lap.

"Why is this so important to you?" she finally asked, the question having weighed on her for the last several weeks. "I mean, I know that Professor Snape is massive part of why we defeated Voldemort, but you've already done so much for him and he's… well, he's just not…"

"Very nice? Or thankful?" McGonagall finished for her, a hint of rueful amusement entering her voice. "No, he's not."

"It must be more than just what he did during the war," Hermione said, the words falling somewhere between a statement and a question.

The Headmistress sighed. "My dear, the war is everything. I've known Severus Snape for almost forty years now, and in that time, do you know how many true allies he had? One. And do you know who that person is?"

Hermione shook her head.

"Lucius Malfoy. Other than that… odious man, we've all betrayed him countless times- myself included. And rather than let us wallow in the misery of our own making, Severus chose, time and again, to stay the course. In doing so, he damned himself to far greater torments then lot of us."

"I thought that you trusted him," Hermione asked, uncertain how to respond otherwise.

"So did I. But when it came down to it, I let the better part of my rage and grief destroy my common sense, and gleefully threw him to the wolves." McGonagall snorted derisively. "Truthfully, I led the pack of wolves most days."

She reached over and patted Hermione's glove covered hand. "You weren't here last year, so you'll not know how bad it was… but I assure you, we- both students and staff- did everything to make his life horrid, all while he was frantically trying to save our unappreciative hides."

"Ginny and Neville mentioned a bit," she said cautiously, not knowing how much the other woman knew about her friends' more clandestine activities.

"We all tried to murder him. Multiple times," McGonagall said bluntly. "And really, last year was simply a microcosm of what happened his entire life. I know for a fact that his father beat both he and his mother for years while he was growing up… and when he finally came to Hogwarts, we hardly protected him any better. Granted, his personality has never been what you'd call charming, but still, we ought to have done far more than sit back and let him champion his own battles. And then Albus…"

The woman sighed again, her face clouded over in anger and regret. "For all that Albus Dumbledore proclaimed him a trustworthy man, he certainly didn't treat him as such; in the end Albus left him hanging, and we all followed his lead. Do you know how many times I saw Severus come back from that madman, tortured within a inch of his life…?"

"Come back from Voldemort, you mean?"

McGonagall laughed, a harsh, hollow sound. "Yes, from Voldemort, although Riddle and Albus were both as mad as march hares in their own ways. Albus could be just as cold and cruel; the difference was, he let others do his dirty work for him." The Headmistress shifted so that she could face Hermione fully. The woman's emerald eyes were fiercely determined as she went on.

"I can't give him back his childhood, or his school years. I can't erase the years of physical and physiological torture. I can't give him happiness, or a measure of trust, friends… any of those things you truly need to truly live. The only thing I can give him is another chance. And that, my dear, is where you come in. You saved his life." For a moment, a contemplative, almost crafty expression filled her gaze. "And whether or not he ever says so, he will feel that a debt is owed over it. He will let you help him even when he won't let Poppy or I do so. Fight him, argue with him. Poke and prod, push him as far as you dare, but just work with him. There is a good man under all that pain and anger, and I know if we only give him a chance to heal, he'll do the rest."

Minerva McGonagall reached forward and patted her cheek. "He's a survivor, just as you are. He just needs enough time to remember that." She stood, motioning Hermione do to likewise. With a practised flick of her wand, the Headmistress transformed the bench back into a rock.

The woman's Scottish practicality apparently restored, she said, "Now come along. It's far too cold to be sitting outside in this weather."

20 January 1999

"I think you're flat out wrong." Hermione put the vial that she was examining down on the stone table with a muted thunk. "Just because Muggle technology hasn't been used to combat Dark magic doesn't mean that it can't."

From his perch upon a tall stool, Snape rolled his eyes. Really, Miss Granger, I know that you are a natural advocate for all things Muggle, but this is taking it step too far.

"Right, because you've used nanotechnology before and found it to be less than helpful in the application of healing potions," she shot back obstinately.

You know very well that I didn't know what bloody nanotechnology was prior to three days ago. However, I don't need to be a theoretical chemist to understand that trying to force two separate kinds of 'technologies' that operate on completely different metaphysical plans to work together is viable, or even a feasible idea.

"And again, I'm going to ask why? Why not? Because no one else has done it before? This is emerging science, even for Muggles, and we won't know if it can work unless we try."

Hermione cut off any reply with an impatient wave of her hand. "We've been at this for over a month now, and even with the addition of unicorn blood, we are not any closer to finding a working solution than when we started. What I'm suggesting is that we approach the problem from a different angle." Picking a stack of papers and printouts that she'd gathered from a Muggle library, she pushed the stack towards him. "If a group of American high-school students can create a revolutionary new way of treating snake bites with nanotechnology, I don't see why we can't do the same for you. Just read the damn articles before you dismiss my idea out of hand."

Hermione rather thought her idea a brilliant one. She'd spent several days researching Muggle venom treatments, and had come across a series of journal articles about a group of youths that had managed to create a medical protocol that used polymer nano-particles to bind antivenin to the toxin in the bloodstream, making it much easier to treat. That idea seemed like the perfect fix for the issues that they were having; the nano-particles could not only bind themselves to the venom in Snape's blood, thus making it simpler to extrapolate and duplicate, but once they had a working antivenin, would also aid in the final treatment as well.

Pity that stubborn mule of a man won't even bother to read up on what I've found. Despite his long-standing affiliation to the Pureblood supremacy movement, I don't think he actually gives a fig for any of those foolish notions... and besides which, he's a half-blood himself.

You do realize that in order for your particular scheme to work, you would have to somehow charm your nano-particles to have an affinity for Dark Magic... and the only way to do that is use Dark Magic? Dark Magic, I might remind you, that you know very little about, and will require some sort of blood price to do so.

Something in Hermione loosened upon reading his statement; sarcastic as it was, they had at least progressed to the point where he was at least considering her idea for it's merits, not just dismissing it utterly out of hand.

After her conversation with the Headmistress, an imp of the perverse had awoken within Hermione, and along with that, a seismic shift had occurred in her relationship with Snape. She wasn't blind; she could see how he was reining in his temper and checking his comments in their daily interactions. Hermione didn't completely buy the Headmistress' idea that he was doing so merely because he felt that he owed her; rather, she thought it was because she could- and would- walk away if he didn't toe the line. And if she left, there would be no further unicorn blood, and no assistance. For all that he was a saviour of the wizarding world, he had also burnt his bridges with wild abandon. Had it not been for Minerva calling in every favour and every scrap of influence that she could, Severus Snape would be in Azkaban; had it not been Minerva, Hermione would not stuck it out to work with him.

But the power balance had shifted, and Hermione took advantage of that fact every way that she could. She asked him endless series of questions, and the new rules meant that he had to answer… politely. Likewise, she questioned methods and conclusions in ways that he never would have tolerated before. Severus Snape had to not just humour her: he had been forced to acknowledge her, Hermione Granger, as an individual, not just as one of the 'golden trio', or as the 'annoying Gryffindor swot'. While the man had not apologized to her- and she wasn't holding her breath for that miracle to occur- in some ways, being able to act and do as she pleased with little concern for reprisals more than made up for everything else.

With a challenging glint in her eyes, she pushed the stack of papers a bare inch away from his folded, long-fingered hands. "Read it, and if you think I'm still a daft pillock, then we'll move on."

With a huff worthy of a third year, he snatched the papers from the table and hurriedly retreated to his more comfortable chair.

You are not a daft pillock. Snape kept his gaze firmly latched on to the first sheet of paper.

"No," she said softly, willing the smirk to stay off her face. "I'm not."

9 February 1999

It had been more than a few days since Hermione had felt anything resembling close to smugness; her nano-particle notion, so promising in the initial steps, had suddenly petered out, and they had not progressed at all in the past week. Every time they got one set of charms to stick, another set would fail; once they'd figured out how to balance one part of the polymers in suspension, they'd been forced to redo another part of the potion because it had gone out of whack. The miserable weight of failure was starting to dog her; it had been her concerted pushing that had sent them down this narrow path, and if it proved to be a dead-end, then it would be quite a lot of time and effort wasted for nothing.

Snape, smart man he was, had not needled her on it. Rather, he had stepped up and started to use his own brilliant brain to work out the kinks.

And brilliant it was, too. Hermione had always known herself as not just smart, but exceedingly so. She'd been at the top of her grade in primary, and had been the best student for her six years at Hogwarts; there had no doubt that had she actually been able to finish her seventh year, she would have taken first honours. But Snape… Snape was in a whole other league.

They had finally settled into an agreeable routine; mornings meant brewing and afternoons were the dissection of what went wrong, as well as planning for the next day. Mondays and Tuesdays were the most productive days; he took his weekly dose of unicorn blood on Sunday evening, and as the week went on and the effects wore off, Hermione would start to see that pinched, grey cast returned to his features. By Friday, he would be a surly bastard once more, and she refused to work with him at all on Sundays.

The unicorn blood had eventually had another, unexpected effect; Snape had finally started to speak again. Hermione experienced a queer sort of sorrow at the raspy baritone husk that his voice had been reduced to every time he spoke. Still, raspy voice or no, his return to speaking had made their fights a lot more… fun.

That thought made her squirm a bit. You must be completely nutters if the first adjective you think of when fighting with Snape is 'fun'. But as crazy as it sounded, she did enjoy their intellectual debates: they would bicker back and forth until they reached the limits of her knowledge, he would assign her several books worth of reading, and then they'd start all over again the next day.

She had tried to explain it to Harry and Ron when they'd come to the Castle several days earlier, and had utterly failed, mostly because they couldn't understand why she didn't mind being around Snape any more. He could be almost decent company, if you didn't find sarcasm to be mortally offensive... which she didn't, as she could dish it back.

More than that, their project occupied all her mental processes; Hermione did not have to think about what she'd done to her parents, or how she was going to explain it to Harry or the Weasleys. There was no room to remember to the long, grinding horror of the months living in tent, or what had happened in Malfoy Manor, or the events of the Battle… she could wrap herself up in the safety of academic arguments and pretend that she didn't feel more than a little manic and scared of the future.

But their current string of failures was making it harder and harder to ignore the nascent bubble of anxiety growing within her. Matters had shifted, and she wasn't just doing this work out of obligation, or even pride; Hermione wanted this to be a success. She wanted Snape to have his chance… and they were failing.

Resolutely, she focused her gaze back on the text in front of her, and began to take notes again. What if we layer the charms using runic calculations…

Her quill abruptly snapped, ink dribbling messily out of the feather, and all over her notes. Reaching into her pocket for her wand to clean the splotch, she found it empty. It also wasn't in the bottom of her bag- she didn't even see the extra pens and quills that she'd place in it- and her anxiety erupted.

"Oh, bugger!" she exclaimed, scanning the surrounding tabletops for her missing items.

"What is the problem?" Snape asked, looking up from his own set of experiments.

"I've just broken my quill and gotten ink all over. I can't find my wand… and I know that brought a couple more biros with me…" She trailed off, aware that she was rambling uncontrollably.

He gazed at her for a long moment, black eyes inscrutable, before circling around his table and gliding over to hers. Stopping in front of her, he remained silent, merely watching her with an air that was distinctly… masculine.

To her shock, he reached out and gently touched her hair with a deft hand; the action was so bewildering that she merely blinked up at him, astonished. Then there was a tug, and Hermione felt her curls come cascading down and slide over her shoulders, the sensation almost sensuous.

His hand reappeared, and in it was her wand. Oh, right. I was using it to hold my hair up… she thought, becoming aware that her heart had stared to pound in a rather unfamiliar, jumpy rhythm. Snape placed the wand carefully on the table, and then reached again for her.

This time, his finger just barely skimmed her temple before giving her scalp another tug, pulling a battered quill from her locks. I bet I have ink in my hair, she thought dazedly as he placed the item alongside the wand. And I must have looked like a mad woman, with all that sticking out off my head…

A third time he touched her hair; fingers carding over the crown of her head in such a way that she was forced to repress a shiver. A biro joined the objects waiting on the table.

Next, two fingers caressed the upper shell of her right ear, and Hermione stopped breathing. Slowly, he withdrew a second biro from where it had been tucked behind her ear, the slow drag of the pen over her skin making her break out in gooseflesh.

"I wonder," he murmured, voice low enough that it was almost smoky, "…what else I might find in your hair if I looked? What else might be lost in there?"

My marbles…she thought, mouth gone dry, and the sharp edge of the table biting into the fleshy part of her palm from where she was gripping it. I've lost my marbles. And funny enough, I don't mind if you have a peak…

Just as his hand came up again, the door to the lab flew open; they both jumped apart, the bustling, rustling figure of Madame Pomfrey coming as unwelcome shock to the system.

Hermione managed to tear her gaze away from Snape long enough to register that neutral expression that slid over the Matron's expression as she took in the scene before her.

The woman said nothing however, and walked over to Hermione, hand outstretched with a note. "Post Owl just dropped this by. I thought it might be important, so I brought it up."

"Thank you," Hermione all but croaked, fingers numb as she took the proffered paper.

"Not a problem at all. Severus, don't forget to come by at four so I can take your vitals."

"As you wish," Snape replied, as the Matron made for the door.

When she looked back again, Snape was firmly stationed behind his own table, and he met her befuddled gaze with a bored and dispassionate one. There was no hint on his face that the previous minute had affected him.

Did I just imagine that whole scenario? she thought, glancing down to confirm that her wand, quill and biros were laid out on the table before her. But the even, measured placement of each item only increased her confusion. I really must be losing my marbles. Snape is a lot of things… and sexy is not one of them. I mean, I don't even like him, and I certainly don't fancy him… Clearly, I need more sleep… or something, because that didn't just happen…

Mechanically, she opened the note. It was from Ron, his scrawl a haphazard as always.

"Hiya love!

George has graciously consented to letting me leave early, so I thought I'd join you for dinner. I'll be at the gates about six- Ron"

Oh, bugger it all! she thought in mingled irritation and unease. The last thing I want to deal with tonight is a hungry, amorous boyfriend!

Snape's feet caressed the stone floors silently, and he revelled in the sheer freedom of being able to wander the long hallways of Hogwarts as he pleased without worry of collapse. Night had fallen hours before, and the Castle had gone gloriously silent and still; he ghosted through the welcoming shadows with a sybaritic joy.

The only thing missing in his nocturnal exploration was the possibility of catching students in the midst of their juvenile mischief and taking points away. However, as the school would not be open to students until the start of September, he would have to settle for a simple walk. But settle he would, and be grateful for it.

Events had finally swung his way; the first dose of unicorn blood, taken almost two months prior had produced a lessening of his maladies so great that it was almost akin to a rebirth. The effect of being pain-free for days at a time had a galvanizing effect on him that was second to none. He could speak, and the wound on his neck had almost completely closed...

Out of nowhere, Snape heard a sound from further down the corridor and paused, surprised to find evidence of the other people living in the Castle; it was late enough that everyone should be abed. Taking stock of his location, he realized that he had gravitated to the Gryffindor wing out of habit. The noise came again, a clear exclamation, and he found himself moving forward, curiosity peaked.

At the end of the corridor, a familiar red-headed figure appeared from one of the many sheltered nooks favoured by students. Ronald Weasley, he noted, was rather more muscle-bound than he'd been as a youth, but he still sported a permanent expression of gormless befuddlement on his freckle-clad face.

Then Hermione Granger appeared from the nook, hair and clothing akimbo, and Snape felt a stab of volatile anger flash through him. How dare she! To risk everything for the sake of a little snogging...

But her next words quickly disabused him of that notion. "Ron, for Pete's sake, can you keep your hands to yourself for once? You said you wanted to go for a walk, not that you planned to shove me in a corner and go for it."

"Blimey, 'Mione, do you have to be so literal minded all the bloody time? You're my girl... it's not like going for a walk and having a snog are any great shocker."

Snape found himself sliding further in the shadows of the hallway, the long-held instincts of espionage prompting him to gather more information instead of revealing himself. He also chose to ignore the flood of relief that had filled him after Hermione's exclamation.

"Ronald, I've said rather clearly that I prefer to wait, and the more you push me on this, the less likely I am to change my mind."

"I love you." The boy's voice went hard and accusatory. "I offered to marry you, and you said no. You don't want to live together either, and I only see you if I come to Hogwarts. Otherwise you play lady of castle and won't come down. Pardon me if the entire situation makes a bloke think that you're not very interested."

"It's not that, I promise..." Hermione's voice trailed off, and it occurred to Snape that she must not have told her former compatriots about her weekly trips to the unicorns. He wondered why; it was no secret that that the two of them were working together. "It's just... complicated, and I need more time."

"So explain why it's complicated, Hermione, because I just don't understand."

Granger made a sound of impatience. "After what happened in Malfoy Manor, do I really need to go into detail about why I want to wait? Why I'm not comfortable?"

"It's been almost a year. The only way to get over something is to confront it, and you can hardly do that if you don't let me touch you."

"Funny how that works; I have to confront my demons right away, but you get to use yours as an excuse anytime things go wrong!"

"That's different! Fred is dead..."

"And quite frankly, Ron, I feel like a part of me died that night." She paused, her next words coming out less aggressively. "I don't know how many times I have to tell you this, but it's not just that one thing. It's that... and my parents, and everything happening right now... my body is the only thing I have any sort of control over..." Granger's voice went wobbly with emotion, and she started to sniffle.

Snape saw Weasley reach forward and stroke her curls; when the woman started to cry in earnest, he moved to put an arm around her. There seemed to be a moment of understanding between the two, until the ginger menace shifted her closer. With another muffled exclamation, Hermione stepped back.

"Would you stop that already?"

"Oh, for fuck's sake, Hermione! What more do you want from me? You tell me that I'm not supportive of you, and then when I try to comfort you, I get yelled at!"

"And maybe if I couldn't feel your prick digging into my thigh, it might actually feel like comfort!"

"I'm a bloke! I can't help that!"

"Well, I can!" Hermione yanked away from the boy, and started down the corridor towards the portrait of the Fat Lady.

"Fine!" Weasley shouted, and with a dramatic whirl of his own started stomping in the opposite direction. "You come find me when you're ready, Hermione. I just can't promise I'll still be waiting!"

Witnessing their fight bothered him more than it ought.

Covertly, he watched her as she bent over a small vial attempting to charm nano-particles, and observed her for signs of emotional distress from the evening before. She appeared tired - which was hardly a new or surprising state - but other than that, there was no trace of her fight with Weasley.

Since she'd started to collect the unicorn blood for him, they'd reached an unspoken truce. While it had taken effort in the beginning to be nice to her- or at least, a simulacrum of civility- it was no longer a hard thing to keep up.

It was oddly humbling to see how she threw herself into the problem of developing an antivenin; sometime during her yearlong sojourn looking for the Horcruxes, she had made the intellectual jump from merely memorizing knowledge and regurgitating it to being able to make creative, breath-taking leaps of logic. He could admit, if only to himself, that he admired her genius, the way she combined the Muggle with the magical...

If they hadn't been working on a task that held such high stakes for him, if their project had occurred ten years earlier... well, he rather thought he would have relished what they were doing. Taken great pleasure in working with such a facile mind and with an able assistant. And she? He had no clue if she was likewise finding their work stimulating.

And that was the kicker; there was a slowly emerging part of him that wanted her to like what they were doing... to enjoy working with him.

Snape no longer looked at her and saw the swotty student, or the stalwart friend of Harry Potter, but a bright, generous woman. Anticipating her daily deluge of questions, trying to stay one step ahead of her thinking - it was a dance like no other.

Despite spending the better part of each day together brewing, Granger and he did not speak of personal matters, and he had only a vague idea what was occurring outside the walls of the Castle. It was easy to assume, therefore, that she had no life outside of what he saw in the laboratory.

Observing that small slice of her other life had roused... certain feelings in him that he was loath to name.

He liked her.

And so you want to be what? sneered a condescending voice in his head, Friends? After all that's happened? You don't think that she is actually interested in anything you have to offer, do you? Be honest: the second this little project is completed, she'll be gone and won't look back. You've made damn sure of that.

And yesterday? Yesterday had been a folly of the worst kind. He hadn't meant to touch her… but that hair of hers had drawn in him in, and before he knew it…

It would take the assiduous, repeated application of Cruciatus before he'd admit it, but Snape found her hair to be absolutely fascinating. It was the utter antithesis of his; curling and vibrant where his was greasy and lank, multi-hued in shades of brown, red and blond mixed about in heady abandon, rather than his unrelieved, stark black lengths.

Granger came in each morning, her hair contained decorously in a neat braid, and as they brewed, it would seemingly take on a life of it's own. Curls would begin to make their cunning escape, to wind about an ear, or slither down her neck in a sneaky fashion. Absently, she would fuss with it, the effort only serving to free the riotous mass from its cruel confines. By the end of the day, it would resemble nothing more than nimbus, and he longed to sink his hands into it to see if felt effervescent as it looked.

She had resembled nothing more than a gloriously demented hedgehog when he quill had snapped and she'd gone hunting for her things; eyes flashing, and her wand, along with the other sundry items sticking up and out of the coiled masses in clear aggression.

And so he had reached out…

Her hair had slid like raw silk over his sensitive fingertips, the sheer tensile strength of coming as a surprise. When he'd pulled her wand out, the entire braid had shifted en masse towards him, a landslide of jasmine-scent chaos, and he'd been lost.

It wasn't until he'd risked peering at her face, however, that the alarm bells started ringing. Her always-expressive amber eyes had gone wide with shock, and the faintest tinge of rose had started blooming on her cheeks. As he slowly removed the biro from behind her ear, he had realized that his discipline and self-control had finally failed him.

He wanted nothing more than to gather that mane of hair in his hands and give it a firm tug; bury his nose in it, and let it devour him whole.

Thankfully- cursedly- Poppy Pomfrey had walked in, and he was saved from making an utter fool of himself.

He did not think he could blame the bout of madness on the unicorn blood. But in all his years of teaching, he had never harboured such thoughts about a student, and he wasn't sure why he was starting to now.

In her corner of the lab, Granger made a low, pleased sound, and something in him stirred at the soft noise. He shifted, uneasy, and the movement drew her attention. She met his gaze without guile or pretence; eyes flicking briefly down vial, she offered him - well, the vial, really - a slight, lovely, smile.

"Almost there, I think," she murmured, her focus already returned to the work at hand.

Snape felt a wave of resentment wash over him and threaten to overwhelm the small measure of peace that he'd found. When in his life did he not want what he could not have? Taking a calming breath, he shoved his emotions into the deep freeze of his Occlumentic shields; felt the corresponding cold composure overtake him.

You don't actually want Granger; you only want what she represents.

Dispassionately, he eyed her once more. Her left hand was covered with ink, and the right sleeve of her robe had a rather large hole in it, likely from the bubotuber pus she'd been working with earlier. The hair had gone frizzy. She looked younger, more vulnerable. You'll get over it, that voice said again. You did once before.

He returned to his own work.

A/N- Ahhh, denial. Not just a river in Egypt...

There were some utterly fabulous comments on the last chapter- Amarenima Redwood, Very Small Prophet, evil-sensei iruka, guest, Luna de Papel, Cate Tyler, Majerus, nancy loves harry potter , teishamarie, and Brightki- you have my most sincere thanks. I've said it before, and I'll say it again- comments mean the world to me, not just because the allow me to see that people are enjoying the story, but because they help me write better. So often, you get so immersed in the plot that you only see what you want, not a more realistic and holistic world view. Critical comments, in particular, are wonderful because they provide that platform to take a step back and think about matters in a more dispassionate fashion.

Very Small Prophet left a great comment, and I've spent the better part of this week thinking on it. In part, it was: "Why is it that Slytherins always owe life debts to Gryffindors, but Gryffindors absolutely never owe them to Slytherins, no matter how often Snape risked his neck protecting the arrogant, ungrateful Golden Trio? The only explanation I can come up with is that children cannot owe life debts to adults because all adults have a moral obligation to protect children. (Do you hear me, Dumbledore?) It would be thoughtful of Hermione (or somebody) to recognize that, even if it still leaves Snape technically (and unjustly) indebted."

I do think that age has to do with some of it- especially given the role that Snape was in as a member of staff, and thus duly charged with protecting his students. But for my head-cannon, there is another, more important factor at play, and it has to do with how one views the world.

Simply put, Slytherins- or at very least, Snape- tend to view the world, and their interactions in a much more formal series of give and take. More old-fashioned notions of honour and debt play into things.

But let's look at the flip side of it; certainly, the Gryffindors had very established ideals of honour and courage as well. Why don't they typically owe people life debts? In part, because the notion of sacrifice for the greater good is built into their communal ethos (cough*Dumbledore*cough)... and unlike the Slytherins, they are very good going in and getting themselves killed, whereas the Slytherins are far more practical, and have a backup plan to get out.

In Snape's case, the way that he has always been treated also plays in why he owes people life debts. As a character, I've always seen Snape as someone who values his own life very little, especially when balanced against the supposed value of other people. As Minerva mentioned in this chapter, when do people champion him? Almost never- and thus, when they do, it's a big deal... and creates a life debt.

So that's my explanation. If any of you have thoughts on it, I'd love to hear it. Happy reading!