Even with his feet so close to the fire blazing in the hearth that only his dragon-hide boots kept his toes from scorching, Severus Snape was cold.

Objectively, he knew the room was warm. It was one of the advantages of the dungeons — being buried below the ground moderated the worst extremes of both scorching summers and frigid winters. And the fire was ferocious enough to heat even a draughty tower room in January, let alone this room in October.

And yet

He refused to shiver, and he most definitely refused to wrap the thick blanket Tilney didn't think he'd noticed her deliver around his shoulders. Giving in to his body's irrational inability to recognise that the room was a comfortable temperature would be yielding to the curse. Not in any large way, true, but I'll be damned if I'll give it even one inch it doesn't have to fight to take.

His arm ached, as if the curse sensed his defiance and was enraged by it. A small smile touched his lips. Good. You have a fight on your hands, whoever you are. I hope you know that.

The smile died. Whoever you are. That was the rub, wasn't it? Potter had spent nearly an hour examining Snape's arm with his wand, concentrating so hard it was a wonder smoke hadn't begin to pour from his ears with the unaccustomed exercise he was giving his brain. At the end of it, he'd confessed himself as unenlightened as he'd been at the beginning.

That had been no surprise, and yet Snape had found himself disappointed. Disappointed, and then furious with himself when he realised that it was because he had, however briefly, allowed himself to hope: hope for freedom, hope for life, hope for a surcease of pain.

To hope for things he could not have, and did not, after all, deserve.

He hadn't even been able to relieve his feelings by verbally flaying Potter to within an inch of his life, either, because of the boy's — the man's — damnable new-found maturity. Nothing is more infuriating than having someone find your most vicious insults mildly amusing.

Which was probably why Potter did it, which meant that he had in some indefinable way gotten the better of their exchange before he went off to find his fellow ex-Aurors with a cheerful Sleep well!

The fire was dying down. Snape roused it to full blazing life again with a flick of his wand. He should go to bed, he knew. The chill he felt could as easily be the product of fatigue as of the curse. Merlin only knew what the time was — sometime after dinner, he supposed, from the untouched plate Tilney had brought at some point before she'd brought the blanket.

He should go to bed. He should go to sleep.

Sleep well!

Snape shuddered, and made no move to leave his chair.

A glimpse of Charity as she'd been — stolen, plundered from her sister's mind, but real — was infinitely preferable to the memory of her upside down, tears of pain and terror tracking over her temples to her hair, to the sound of her voice cracked and hoarse with agony and fear.

Please, Severus we're friends.

He had no illusions that tonight of all nights he might find only oblivion in sleep. No, what waited for him in his bed was another night of being put to the choice, over and over again. Of making that choice, over and over again.

Of turning the blank face of indifference to the woman who had kept her faith in him, even then, while on his forearm the Dark Mark burned and writhed as if it, if not its maker, could tell he was a traitor in his heart.

Please, Severus we're friends. Had they been? She'd defended him, even to her own flesh and blood, when all the world knew him as a murderer. Would I have done the same, if our positions had been reversed?

No, probably not. Charity had believed the best of him, as she had of everyone, because she couldn't entirely believe that her own inherent decency wasn't somehow hidden within everyone. Whereas I know that it is darkness, not decency, that lies hidden in us all.

A sudden and very Gryffindor hammering on the door made him start slightly. Potter? And there it was again, the flare of infernal, irrational hope, before his wards told him it was a different Gryffindor pounding on his door as if to wake the entirety of Slytherin House from sleep. Granger.

He was tempted to leave her standing in the corridor, a little encouragement to her and the others to moderate their enthusiasm for calling on wizards unannounced and uninvited, but she showed no sign of reducing her assault on his door.

The moment it opened to her she came storming up the corridor as if to battle, robe billowing behind her like a battalion flag. "Is it true?" she demanded.

Snape turned a little, giving her the look that had always made even his N.E.W.T students quail. "You will have to be more specific, Professor Granger. Is it true the sun rises in the east? Most certainly."

Her appearance made it clear that she was too emotional to give even the most basic consideration to maintaining the decorum appropriate to a member of staff: only one arm was through the sleeve of her teaching robe, the other side of it dragged hastily over her shoulder, and a significant portion of her hair had escaped its confinement and stood out around her head in reckless curls. Her next words made it clear she was also too emotional to grasp his admonition for her imprecise language. She put her hands on her hips, dislodging her robe. "Is it true, what Harry said?"

"Since I have no idea what Potter has told you …" Snape drawled, and saw the colour rise in her cheeks with a sense of satisfaction.

"He said your curse is worse," she snapped. "Show me."

Snape drew his left arm protectively to his chest, noticed he was doing it, and scowled. "I am not an exhibit, Granger." Yes, that was it. Is a wizard to have neither privacy nor dignity in his own quarters? His reluctance to show her the withered flesh was a very reasonable desire for a little choice in the matter, nothing else.

Choice he was apparently to be denied, because Granger stomped across the room in her thick-soled Muggle shoes, robe trailing and flapping behind her, and actually grabbed his left wrist. "Show me!"

He seized her wrist in turn. "Professor Granger. I am pleased to be able to say I have lost all familiarity with Muggle manners, but allow me to inform you that in our world one does not manhandle a wizard." He paused long enough to let that sink in, and then added silkily, "Without his … express … invitation."

For a moment he had no idea why he'd said that, and then as Granger blushed an unbecoming crimson and released him, before taking a step back, he realised that his instinct to select the most discomfiting remark possible hadn't waned one iota in his years out of the classroom. The realisation made him smile, which made Granger take another step backwards —

Which made her catch her heel in her trailing robe and pitch backwards.

His Mobilicorpus caught her and lifted her up before she could pitch into the fire and incinerate herself. Which would have been a valuable lesson, but Poppy deserves her sleep.

"Thank you," Granger squeaked from mid-air. "Um — could you put me down now?"

Snape pretended to be thinking it over, while Granger stared determinedly at the ceiling as if she was above noticing the humiliation of being suspended above the carpet. "Has your control over your Finite Incantatem become unreliable?"

She shook her head, still not looking at him. "I'd rather not just drop, that's all."

Tempting though it was to let her down with a jolt, Snape lowered her slowly until her feet touched the carpet before he released the spell. "Either take that robe off or put it on properly before you kill yourself."

"I hate this thing," she said, struggling to locate the armhole. "I feel like I'm playing dress-up."

"That is the fault of your own attitude, not the robe," Snape said severely.

Granger finally managed to get herself properly dressed, and settled the robe in place with a firm tug on its lapels. "I don't know how you managed to never get your sleeves in any of our cauldrons. If it wasn't for the protective charms you gave me, this would be all to tatters by now."

"Practice," Snape said. He gave her a thin smile. "I assure you, after a decade or so, it will come naturally."

That, he realised, was a mistake, for her eyes narrowed at the mention of her future teaching career. "You've given up."

"Not in my nature," he said coldly. "As you, by now, should know."

"Is it worse? The curse? Like Harry said?"

He pressed his lips together, and nodded.

"Let me see — oh, don't look at me like that! I thought the potion was working, if it isn't, I have to see."

"It was working." Reluctantly, Snape unbuttoned his coat-sleeve once again. "But apparently no longer." He stared into the fire as he revealed the cursed flesh to her, but he couldn't close his ears to her cry of dismay.

The rustle of her robe was the only warning he got before she was kneeling by his chair, trying to take hold of his wrist again.

He flinched away. "Don't touch it, you fool. Does the term 'Dark magic' mean nothing to you?"

She stared up him. "You let Harry examine it. For hours, he said."

"Potter is an Auror. One presumes the Ministry insists on at least basic competency in precautions against contamination."

"Oh." Biting her lip, Granger looked closely at the grey blight on his skin, but she made no further move to touch him. "How long? Since it began to get worse?"

"A few days." A few days since he had realised it was no longer reducing, and only hours since he had realised it was expanding with sickening speed.

She frowned. "Is it — you've used a lot of magic in the past few days. I know Legilimency can be demanding — today, and before, with — before. Is it, have you —"

"Merlin's white whiskers, Granger, spit it out or shut up!"

"Is using your magic making it worse?" she blurted, rubbing her own forearm. "Because if it is …"

"Don't worry," he said acidly. "Breaking Bella's little mischief wouldn't kill me, even if your assumption was correct. Which it isn't, so kindly spare me any expressions of guilt."

Granger stared up at him. "But that means it is my fault. It must be a rebound — from the potion — I was trying to help, but I've made it worse!"

The thought had occurred to Snape as well, and interfering busybody and insufferable know-it-all had been the mildest of what he'd called her in the privacy of his own head, the only place I seem to be able to get any privacy at the moment.

He was preparing to treat her to an assessment of her character and competence that would have made any remarks he ever made to Neville Longbottom seem like effusive praise when two tears trickled down her cheeks, quickly followed by their fellows.

Oh, for Even with his extensive repertoire of profanity, Snape couldn't think of words strong enough to express his exasperation. "Granger, stop it."

She cried harder, covering her face with her hands. It was only a minimal improvement, as her hitching breath and shaking shoulders were not in the least concealed. Normally, reducing a student to well-deserved tears was a pleasure to be prolonged as long as possible, but Granger's noisy self-flagellation was disquieting.

Irritating, he corrected himself. It's irritating.

"If the exacerbation is caused by the potion — Professor Granger, kindly compose yourself. This over-emotionalism is counterproductive."

Granger raised a blotchy, tear-streaked face. "If I've k-killed you …" Her voice trailed away and she gave a gulping sob.

"Then I give you full permission to indulge yourself in an ostentatious display of your choice at my funeral. For now, do try to act like the Potions Professor you are." He narrowed his eyes at her, and she nodded, gave one more gulping sob, and wiped her face on her sleeve. "And if you blow your nose on the sleeve of your robe, I will personally make sure Minerva dismisses you before the end of the week." He Summoned a handkerchief and held it out to her. "Here."

She took it and blew her nose with typical Gryffindor enthusiasm. Thankfully, she made no effort to give it back to him, but tucked it into her sleeve. "What do you need me to do?"

Leave me in peace and quiet until this reaches its inevitable conclusion, Snape thought. Aloud, he said, "A full analysis of the alchemical changes produced by your changes to the original recipe." That will take her at least a week, given the other demands on her time.

Granger nodded. "I can do that."

"I wouldn't have suggested it if I thought it beyond your capacity," Snape said as repressively as he could.

She stood up. "I'll get started now."

"No, Professor Granger, you will get some sleep and start tomorrow with a clear head." Even with Bellatrix Lestrange's knife and the knowledge of the curse she'd used, the process of breaking it would be difficult. Snape had no desire to undertake it with Granger half-hysterical from lack of sleep. To make sure of it, he added, "That way there is less danger of you repeating your mistake."

Her expression crestfallen, she nodded. "Will it — will you be alright?"

He raised an eyebrow. "Eager to reprise your role as an angel of mercy?"

"No! I just meant — until Harry can figure out who's doing it, and make them stop. Do you still have … time?"

"I'm not about to drop dead at your feet, Granger, unless slain by your execrable reliance on euphemism."

Instead of flinching, Granger smiled. I really must be losing my touch. "Good," she said. "Because — and I'm not supposed to tell you this, in case he's wrong and you get your hopes up for nothing — Harry's almost positive he's seen the same spell signature somewhere before. He and Ron and Neville are up in the Room of Requirement working through a list of possibilities. Good night."

Snape sat where he was for a long time after she left, staring into the fire until it was little more than glowing coals, trying and failing and trying again to crush the spark of utterly unreasonable, completely undeserved, wholly irrational, hope.