Whether Dumbledore wasn't as good at Side-Along as Severus, or whether it was because there were so many of them, Hermione wasn't sure, but she was nearly sick when they arrived at their destination. She wasn't the only one, by the gagging noises Ron and Harry were making, but sadly it did mean that Severus let go of her hand in a hurry. Recovering her balance, she glanced at him; his eyes flicked to the others for a moment, checking whether he was being observed or not, before he gave her a very, very brief smile and turned away to survey their surroundings.

Copying him, she looked around. They were standing on a rocky outcrop at the foot of a cliff which was just barely big enough for the five of them; there was a breeze, but it wasn't cold. Venturing closer to the edge, she peered over cautiously – she wasn't fond of heights. It wasn't too far down, and there were plenty of ledges and so on. "Where's the cave, sir?" she asked as Dumbledore and the boys joined her.

The Headmaster pointed with his good hand. "Along the cliffs to the right is a tunnel of sorts through the rock. It is easiest to climb down here and swim along; unfortunately the tide is coming in, or it would be possible to walk part of the way. It would be best if we leave our robes and other encumbrances here, I think."

Despite her fear of heights, the climb wasn't that bad, Hermione was relieved to find; even with only one good hand, Dumbledore managed it easily enough. The boys followed, bantering playfully with one another and occasionally glancing up to check she was all right; Severus was somewhere behind her, bringing up the rear. She had remembered to braid her hair back out of the way – just as well, with the increasing breeze – and it was easier in the dark when she couldn't really see the drop below, as they climbed down towards the surf.

Smothered yelps greeted Harry's and Ron's descent into the water; Hermione understood why as soon as the waves hit. Holy hell, that's cold! Even Dumbledore looked uncomfortable, as he made a show of tucking his beard into his belt out of the way, and she heard Severus hiss very softly as the water got past his waist. At least she had had the presence of mind to keep her jumper on, she reflected, idly watching the way his shirt had turned all but see-through as it absorbed more water. That was a complication she didn't need, and a distraction that was probably a bad idea.

At least they could all swim. Ron turned out to be the worst, but he was managing a decent attempt at a doggy-paddle. Severus had apparently got bored of keeping pace, rapidly overtaking them; he was at the crack in the rocks that apparently led to the cave by now.

"Severus, nobody is impressed by your showing off," Dumbledore called, his irritation not quite hiding the fact that he was a little out of breath. It was hard to tell in the darkness, but Hermione was reasonably certain that the younger wizard's response had been an obscene gesture.

"Really?" Harry murmured, doing a passable front crawl alongside her; he had been humming the Jaws theme music and was clearly in one of his dafter moods. "Nobody's impressed?" He grinned mischievously at her. Without replying, Hermione hit him with a non-verbal weak Impediment Jinx, freezing him in place long enough for him to sink. He surfaced spluttering, coughing and laughing. "That's what I thought."

"Harry," she said sweetly, "what do you think is going to happen if he hears you making jokes about things you're not supposed to know? There are a lot of opportunities for you to have an accident, and I won't be remotely sorry."

"Why do you think I waited until he was too far away to hear?" he retorted, entirely unrepentant. She ducked him again and swam faster, gripping her lit wand between her teeth as she followed Dumbledore and Severus into the tunnel. It seemed to be a long time until she could haul herself out onto the rocky steps alongside the older wizards, who were both ignoring one another as much as possible as they dried off. Severus' shirt really was clinging to him, she noticed, and tried not to stare.

"What now?" she asked, shivering, as the boys crawled out of the surf after her.

The Headmaster gestured to the mouth of the cave. "Our destination lies through there. It is, quite naturally, warded..." He trailed off, and he and Severus both approached the cave to examine the rocks around it. She followed, flanked by Harry and Ron, and they finished drying themselves off as they waited; the cave was small and shallow and clearly didn't lead anywhere, so obviously there was some sort of concealment in place.

Finally Dumbledore laid a hand on the wall decisively. "Here." Severus nodded agreement and stepped back a pace as the Headmaster drew his wand and pointed at the place he had touched; the outline of a door appeared briefly and faded. Both wizards resumed their examination, before Severus abruptly snorted in amusement and Dumbledore shook his head.

"Oh, surely not. So crude."

"It is rather typical of him," Severus noted dryly, looking around. "Come here, you three. We may as well get some sort of educational benefit out of this little trip; see what you can sense here. You should know what the Dark Lord's magic feels like."

Obediently they moved closer, tentatively touching the wall and trying to work out what they were supposed to be detecting.

"Anything?" Dumbledore inquired.

Ron gave up first, shaking his head. "Not really, Professor. I can tell there's magic there, now I know where to look, but I've never been much good at this sort of thing. It tingles, that's the best I can do."

"It feels weird," Harry said slowly, staring at the rock with an odd expression on his face, "but I don't know why, exactly."

Hermione only shrugged noncommittally, wiping her hand on her jumper. She had felt it all right, a dark and insidious sort of heat; Severus had told her Voldemort's magic was fire, but this wasn't flames, it was something more subtle, almost feverish. "What sort of ward is it, sir?"

"A sacrificial barrier," Dumbledore said, sounding rather disdainful. "One must make an offering in order to pass through."

"An offering of what?" she asked suspiciously.

"Blood," Severus provided, sounding bored. "I fail to see the point, frankly. It isn't powerful enough to require much. Weasley, time to contribute."

"What?" Ron protested. "Why me?"

Severus gave him a steady look that wasn't quite a glare. "You tell me. Strategy, remember?"

Harry and Hermione exchanged baffled glances as Ron stared at the floor; finally the redhead sighed. "Fair enough, sir. Anyone got a knife?"

Dumbledore produced a blade from somewhere in his clothing and handed it over without comment, as Hermione asked in exasperation, "Can someone translate, please? Why Ron? Is this a pureblood thing?"

"Nope, it's a logic thing," Ron said ruefully, accepting the knife. He pointed to Harry and then to Dumbledore with it. "I'm not one of the most important people here." He pointed to Severus. "I haven't got the Dark Mark doing weird things to my blood." He pointed to her and grinned. "And I'm not a girl."

"You sexist, chauvinistic pig," she replied calmly – she said it to Ron, but she meant it for Severus, who wasn't looking at her and had a suspiciously blank expression on his face.

"Are you volunteering, Miss Granger?" Dumbledore asked, sounding amused.

"I didn't say that."

Harry stifled a laugh and looked around at Severus. "Does the Dark Mark actually affect your blood, sir?"

"Probably not enough to affect this barrier, but it's better not to risk it. Besides, I spoke first." Severus smirked and gestured to Ron. "While we're young, Mr Weasley. Don't slit your wrist or anything. A few drops will be sufficient."

When the blood hit the rock, the outline of the arch appeared again, and the stone inside it faded away to create another tunnel. Hermione healed the small cut on her friend's arm as Dumbledore stepped through, and they followed him onto the shore of an underground lake in a huge cavern, lit only by a faint and rather ominous-looking greenish glow in the distance. "How delightful," the Headmaster said mildly, still sounding amused. "Be careful not to touch the water."

"Is it just me, or does this not make sense?" Harry asked aloud as the five of them began to walk along the edge of the lake, looking for... something.

"How so?" Hermione asked.

"Well, this Horcrux seems a lot better protected than the others have been. I dunno what Malfoy did with the diary all those years, but he didn't seem bothered about giving it to Ginny so he obviously didn't know what it was. The diadem was just sat in the Room of Requirement, and the ring was in the ruins of their old house, wasn't it? So why is this one so well guarded? There's obviously some kind of creepy monster in the lake, probably more than one. And the blood barrier spell..."

"That's a good question, Harry," Dumbledore agreed quietly. "I doubt we shall ever know the answer, though. Ah, here we are..." He stopped at a point that looked indistinguishable from any other along the lake shore and began cautiously making passes in the air over the lake with his good hand, before seeming to grab hold of something; holding his wand awkwardly in the blackened fingers of his other hand, he tapped his fist, and a corroded-looking copper chain appeared. He tapped the chain, which rattled and began to move, and a small boat surfaced from the eerily smooth black water of the lake and drifted innocently over to them.

"Harry's right, this is daft," Ron muttered as they stared at it. "You-Know-Who would be stuffed if he ever needed to get at this one in a hurry, wouldn't he? D'you reckon the boat's cursed to sink half way across, or something?"

"No, I shouldn't think so," Dumbledore said cheerfully. "We do, however, have a problem." He touched the prow of the boat with a finger. "This is only large enough for two, but it will only allow a single wizard to travel within it. Harry, as you are not yet of age..."

"Everyone keeps rubbing that in," Harry muttered good-naturedly.

"Quite. In any case, the charm will not apply to you, but that still leaves us with three of our party who have no means of travelling across the lake..."

"Two," Severus said abruptly, staring at the boat through narrowed eyes. "I can get myself over there. The Dark Lord doesn't need to use a boat either... Potter's right, this doesn't make sense."

The Headmaster raised his eyebrows. "I had assumed such methods would not be possible here."

Severus shook his head. "No, there is nothing in the air preventing flight – a broom wouldn't work, naturally, but nothing else. I suppose he had no reason to disable it; I don't know anyone else who can do it."

"Wait," Harry said, bewildered. "You can fly without a broom?"

The ghost of a smirk crossed his face. "Yes."

"Cool," both Ron and Harry said immediately, and Hermione stifled a laugh. Boys.

"Can you teach us?" Harry begged.

"No."

"Sir..."

"You asked if I can, not if I would. I can't. Or, rather, you can't learn."

"Why not?" Harry protested.

Severus sighed. "We don't have time for a full explanation. The only way I know of learning this is the way I was taught, which was somewhat brutal and involved being repeatedly pushed over the edge of high places until my need to survive yet another fall was strong enough to override the logic circuit in the brain that says humans cannot fly. Small children frequently achieve some form of flight when their magic first manifests, but once they are old enough to understand that isn't possible, they lose the ability. I don't know how the Dark Lord learned it, but that is how he taught me. None of the others had the same view of pain and survival to pick it up."

The boys subsided, evidently unable to think of an argument. Dumbledore regarded them all thoughtfully. "Unless you are willing to take passengers, Severus, we have a problem..."

"I have never tried to carry anyone else." Severus eyed the water distrustfully. "I do not want to find out what happens to anyone who falls in that."

"Then I am afraid Miss Granger and Mr Weasley will have to remain here..."

"That's not fair!" Hermione protested, hearing Ron echoing her.

"I did try and dissuade you from accompanying us anyway," Dumbledore pointed out gently.

"Can't you send the boat back?" Ron asked hopefully.

"If something goes wrong – if there is something over there we do not expect – we may need to leave in a hurry. I am sorry. There is no other way."

"We can't just sit here in the dark not knowing what's happening," Hermione said, despising herself for the pleading note in her voice and trying not to look at Severus too obviously. It was too dark to read his expression but she hoped he was sympathetic; it seemed there really was no choice. "We'll go mad."

"Hmm," Severus said distantly, narrowing his eyes thoughtfully, before abruptly stepping forward and reaching for Harry's head; Harry yelped and jumped away, leaving several black hairs behind in the older wizard's fingers.

"What was that for?" he protested, rubbing his head.

"Don't be such a wimp," Severus told him dismissively, touching his wand to the hairs. "Resonatus." He held the hair out towards Hermione. "It won't work terribly well, but this will enable you to hear most of what Potter hears, at least. It is too far away for you to be able to see what is happening, though."

He had angled his body to block their hands from view; smiling a little, she took the hair from his hand, brushing his fingers with hers and suppressing a shiver. "Thank you, sir," she said politely, giving him a grateful look that he returned with a not-quite-smile before turning away.

"I will see you two on the other side," he told Dumbledore and Harry, putting his wand inside his coat and taking a couple of steps away; pausing for a moment, he loped forward two strides and jumped, vanishing quickly into the shadows.

"I didn't even see how he did it," Ron complained. "I can't believe we're being left behind, either."

"Are you going to moan all night?" Hermione asked, closing her hand over Harry's hair. "Because if you are, I'll feed you to whatever's in the lake." She looked at Harry. "Give us a commentary, please?"

He nodded. "Of course." His voice had an odd echo, since it was also coming from the little clump of hair; he grinned. "Cool. See you soon, then."

Rather forlornly, Hermione and Ron watched them climb into the small boat and disappear into the darkness. A light had appeared from the green glow across the lake; Severus, presumably, letting them know he had reached the source.

"Well, this sucks," Ron said finally, sighing and finding a rock to sit on. She came and sat beside him, both of them bending to get closer to the hair.

"It really, really does," she agreed morosely, staring at the tiny little point of wand light in the distance.

After a few moments, Harry's voice reached them; he sounded oddly tinny and echoey, but his words were clear enough. "Can you guys hear me?" Hermione lifted her wand and flashed a light briefly in response. "Once for yes, I hope that means. You're not missing anything so far, except there are dead bodies in the water, which is really, really creepy. They can't hurt us, can they?" he added worriedly.

Dumbledore's voice sounded even more distorted. "No. We have nothing to fear from the dead."

"If you say so, sir." Harry didn't sound convinced, and Ron and Hermione grinned at each other at his doubtful tone.

A few minutes passed as they watched the little lights getting closer to one another beside the faint green glow. Finally Harry's voice reached them again. "Okay, well, we're here. It's a tiny little island – well, it's a rock, basically. There's a pedestal with a basin on top of it, full of green liquid – that's what's glowing. Do you know what it is, sir?"

"I am not sure," Dumbledore said thoughtfully. "The Horcrux is inside the basin, clearly, and the potion has been protected by charms to prevent it being interfered with in any way. I suspect it is intended to be drunk. However, I do not know what it is..."

There was a soft noise that turned out to be a very distant sigh of impatience, before Severus' voice spoke. "How fortunate you chose to bring a Potions expert, then. Get out of the way, Potter, and let me look at it. Ah... of course. Because this wasn't difficult enough already. Damn."

"What is it, Professor?" Harry asked, as Ron and Hermione leaned closer to listen.

"It is somewhat theatrically called the Potion of Despair."

"Is it a poison?"

"In a manner of speaking. It won't kill you, at least not immediately, but you'll wish it had. I have never seen this, only read about it... I wonder where he got it from?"

"You didn't brew it?"

They heard Severus bark a rough laugh. "Use your head, Potter. You already know the Dark Lord did not see fit to trust any of his minions with the knowledge of what he was doing. He chose to use Pettigrew to brew the potions that sustained his life prior to his return, rather than include even one other person in the plan. However, he certainly did not make this himself – very few would be capable of it. I am not sure even I could manage it. The charms protecting it are his, but not the potion."

"What, exactly, does it do, Severus?" Dumbledore inquired softly.

"Quite a lot of things." Hermione was amused to note that Severus' voice had altered to his usual lecturing tone, the one he used in class when he got caught up in whatever he was talking about and forgot to sound contemptuous or nasty. She could picture his expression, too, his eyes glittering with interest. It's a shame his voice sounds so weird, she mused idly.

Severus continued, "Primarily, it causes physical pain – more specifically, agonising stomach cramps. After a few minutes – just long enough for the drinker to start adjusting to the pain – the mental effects come into play. It mimics the effect of a Dementor's presence, forcing the drinker to relive the very worst moments of their lives, but rather than merely remembering them, you are plunged into a full hallucinatory multi-sensual replay – sight, sound, scent, touch, taste and emotion. Depending on how strong it is and how much you have to drink, it may wear off after a few hours, it may drive you insane, or it may simply kill you slowly over several days."

"Well, bugger," Ron said from their seat on the rock, neatly summing up Hermione's opinion. He added, "You're right, it is really weird that he's protected this one so much more strongly. Why do you reckon that is?"

"I don't know. Maybe this was his first one, or something. Maybe it's the one that's most important to him, which probably means it's something of Slytherin's? Shush, I'm trying to listen."

He subsided, and they listened as Harry asked uncertainly, "What do we do now?"

Dumbledore said distantly, "Neither I nor you would survive drinking it, Harry."

"Don't you bloody dare!" Hermione snapped, turning to glare at the distant glow.

"He can't hear you, Hermione," Ron pointed out, and flinched when she glared at him. "I'm just saying..."

"And Professor Snape would?" Harry asked doubtfully after quite a long pause that made the two left behind on the lake shore really, really wish they could see what was happening.

"I do not know, Harry."

They heard Snape growl in exasperation. "Merlin save us from literal-minded Gryffindors! Get out of the way."

A few odd sounds echoed through the little clump of hair, before Harry said blankly, "Oh. Well, I guess that would work."

Rather pointedly, Hermione aimed her wand towards the island. "Lumos maxima!" The flare of light lasted less than a second, but it was enough to make her point.

"Sorry, guys. Professor Snape just created a goblet and drank some of the potion. He didn't swallow it, just held it in his mouth for a minute while he made another basin on the floor, then spat it into that." His voice dropped to a whisper. "It's kind of gross actually." He spoke again, more loudly. "Does this mean it won't harm you, sir?"

"No," Severus said distantly. "There are a lot of toxic ingredients in this potion. Fortunately, it has been here a long time and has lost much of its efficacy. It's certainly not going to kill me, but it is not exactly pleasant."

"Never mind the bloody potion, I'm going to kill him," Hermione told Ron calmly. "For God's sake, if I'd known he was going to pull a stunt like this I never would have told him we were going out tonight."

Her friend grinned at her as they listened to the distant noises. "Well, we'd be in trouble if he wasn't here, wouldn't we? Dumbledore didn't know what the potion was. And one of them would have had to drink it anyway, and you heard what Snape said it did. One of them would've been seriously hurt. I don't think they'd have thought of spitting it out."

Despite herself, Hermione smiled in rueful acknowledgement. At least I picked a smart man... "You'd need a very twisty mind to think of it," she agreed. "And really, we're after something protected by the Dark Arts and a potion, so I guess we did need an expert in the Dark Arts and Potions. I'm still going to kill him, though."

"Can you do this any faster, sir?" they heard Harry ask. "I'm not criticising," he added hastily as Hermione smiled, picturing the glare that would be being directed at her friend. "I just thought it would be easier to get it over with quickly."

They heard Severus spit to one side and cough before answering. "No, I cannot. The enchantments are on the potion as well as the basin; I have to hold each dose in my mouth long enough for the spells to evaporate before it is possible to spit it out. If I did not, it would merely reappear in the original basin."

"Can we help, as you're not actually drinking it?"

"He's being a bit obvious," Ron noted. "Even Dumbledore's not going to believe Harry's asking because he's worried about Snape. I'm guessing Snape doesn't realise we know what's going on?"

"You're still alive, aren't you? Shush."

Severus replied quietly, "No. Don't distract me, please. I need to concentrate, or I am going to start hallucinating."

"Damnit," Hermione whispered, biting her lip. "You stubborn prat, Occlumency doesn't mean you can do everything..."

"He sounds all right," Ron said awkwardly, trying to be comforting and failing miserably. "He knows what he's doing... Lumos," he added, obviously realising he was getting nowhere and appealing to Harry for updates.

There were some scuffling noises and Harry's voice came through in a muffled whisper. "Sorry, wanted to try and get out of earshot. He's okay, Hermione, at least I think so. He's got his eyes closed, but he's standing normally and breathing okay, and he hasn't swallowed any of the potion. He's not sweating, or clenching his fists. I dunno what else I'm supposed to be looking for but he looks okay."

"See?" Ron said hopefully.

Hermione sighed. "That doesn't mean a thing, Ron. He can dust himself off and walk away from the Cruciatus like nothing's happened. You saw him acting normally just hours after I told you he'd been tortured almost to death. Just because he looks okay doesn't mean he is."

"Foolish Gryffindor." Severus' voice was a muted growl. "Stop worrying."

She grinned despite herself, and Ron laughed. "He wasn't talking to Harry, was he?"

"No," she agreed, shaking her head. "Sneaky bastard."

By the sound of it Harry was trying not to laugh as he continued his commentary. "See? He's fine. He's more than three quarters of the way through the potion, too. He's not spitting it so accurately now, and it's still pretty gross, but it's fine. I can't see the Horcrux yet though. Hang on, he's opened his eyes and stopped drinking..."

They heard Severus say very clearly, "Oh, fucking hell."

"Severus?" Dumbledore asked sharply.

"I'm being Summoned."

There was a faint splash and a gagging sound, and Harry whispered, "He's just swallowed a gobletful. I guess there isn't time to wait and spit it out now. He's gone a bit paler..."

"Oh, God," Hermione breathed, clutching Ron's arm.

"Severus..."

"There's no time, Dumbledore. Shut up," he said thickly. There was a scrape of metal on stone and another cough, before something clinked. "I've got to go."

"He's just scooped something up in the goblet," Harry's voice explained in a whisper. "He drank the potion around it and spat it at Dumbledore..."

Further commentary proved unnecessary as the shadows over the lake moved and blurred and resolved themselves into Severus himself, landing nearby with a scrape of his boots on the wet rock and starting to jog along the lake shore past them with his head down.

"Be careful," she whispered uneasily, as Ron awkwardly squeezed her arm and stared fixedly in the other direction, pretending he wasn't there.

Severus looked up and met her eyes for a moment; he looked a little ill, but she'd seen him look far worse, and his eyes softened slightly as he looked at her, crinkling at the corners in his usual almost-smile. "I will," he replied without moving his lips, so softly she almost didn't hear him, before he accelerated into a run and vanished into the darkness and Harry's voice reached them as he started questioning Dumbledore about the object they had found in the basin.

---

Severus nearly concussed himself travelling through the tunnel by air instead of swimming, but he didn't have time to be more careful. He threw up when he reached the outcrop where he had left his outer robe, gagging and retching before spitting a fair amount of seriously disgusting-looking green slime into the sea. Resisting the urge to start quoting The Exorcist, he used Aguamenti to rinse his mouth out and wash the worst of the salt away in case anyone wondered why he had been to the seaside tonight. Cramps gripped him, and he could still hear screaming and sobbing in his head; Occlumency at least meant he wasn't seeing the images that accompanied it, but the auditory hallucinations were proving too difficult to ignore. Spitting bile, he doubled over, pressing his fists to his abdomen before forcing himself to straighten up and retrieve his clothes, finding his robe and mask in one of the pockets as always.

It was hideously dangerous to answer a Summons in this condition, he knew that, but it would be more dangerous not to answer at all. The time was wrong, and all his instincts were screaming at him; he knew in his heart that this was it, that the Dark Lord was planning to attack. Why did everything have to happen at once? There was no time! Trying not to tremble, he slid a hand under his sleeve to press against the burning Dark Mark and concentrated.

He was glad that he was usually the last to arrive; everyone else could answer immediately, but he usually had to get off the school grounds first, or in this case get out of the cave and back to the cliffs. It meant that on this occasion there was nobody else to witness it as he fell to his knees and tried to stop himself fainting in the aftermath of Apparition, momentarily disorientated. The cramps weren't bad, and the memories assaulting him could have been a lot worse, but he still felt a little off colour.

Slowly he began to walk across the gravel drive and manicured lawns of Malfoy Manor, concentrating on his breathing, reaching for Occlumency and steadily pushing away his awareness both of the pain and the onslaught of memories. He relived that night in his dreams quite a lot, what little he remembered of it; he'd be damned if he had to do so while he was awake as well. By the time he reached the doors of the mansion, the hysterical, keening, choked sobs had faded to the very edge of hearing and the cramps were bearable; that was probably as good as it was going to get. He could still taste the potion on his tongue, under the sourness of bile and vomit; peculiarly, it hadn't actually tasted that bad. There had been a bitterness to it, since one of the main ingredients was absinthe and the wormwood was strong, but the overall flavour had been somewhere between aniseed and peppermint.

He hurried to the usual meeting hall, removing the mask that hid his features as he bowed to the figure at the head of the table. "My lord."

"Severus. How good of you to join us at last. I trust we aren't inconveniencing you too much?" The sarcasm was a bad sign; he didn't want to imagine what the Cruciatus would do to him in this condition.

"My apologies, my lord. Dumbledore... I came as soon as I could." His master wouldn't accept excuses, which was just as well, since he couldn't think of any. Oddly, Voldemort didn't either insult him or curse him, instead waving him to his usual seat and standing up, beginning to pace along the table. Worryingly, he was smiling, which Severus didn't like. Anything that made the madman smile was likely to be unhealthy.

Voldemort stopped behind the Malfoys. Narcissa looked nervous, and by the look on her face was trying to hide it and look proud, but she had grown increasingly ragged around the edges of late. Lucius' expression was wooden; he was unshaven and his grey eyes were bloodshot, staring fixedly straight ahead of him. Draco sat beside his father, confirming Severus' suspicions; the boy looked petrified as Voldemort laid a bony hand on his shoulder.

"My friends, young Draco here has done well by us tonight. A short while ago he found a path into Hogwarts that will accommodate all of us; now he informs me that Dumbledore is absent for the evening." The red eyes stared briefly at Severus with an expression that promised punishment later for not revealing that himself; Severus bowed his head indifferently, no longer caring. He didn't intend to be around for it, not if things really were coming to a head.

"So, my loyal followers," Voldemort continued softly, "if you are agreeable, tonight we will enter Hogwarts and take over. By the time the old fool gathers any opposition, it will be too late." He clapped Draco on the shoulder. "And our youngest brother here will be able to carry out the second of his tasks."

All three Malfoys stared at Severus now. Narcissa was pleading, Lucius looked grim and Draco looked about to faint; Bellatrix, on her sister's other side, gave him a wide, eager smile that was almost as frightening as the Dark Lord's. Severus ignored them all, his mind racing frantically.

"My lord, if I might make a suggestion?" he said quietly, raising his head; he was one of the few who stood high enough to risk interrupting.

The red eyes narrowed a little and there was a definite note of warning in his voice as Voldemort said coldly, "Speak."

"Perhaps I should return to Hogwarts ahead of the rest of us," he said slowly, scrambling for the right words, keeping his voice steady and his face impassive as though he was merely speculating aloud. "Many of your followers have kin in Slytherin House; surely, if we can, we should try to keep them away from any conflict that might arise. It would also be prudent to make sure that the Headmaster has not returned unexpectedly; I do not know when he is due to come back tonight. And... my lord, people are irrational about the safety of their children. If they escape unharmed, we will find far less opposition as we take power; one child accidentally hurt could cause unnecessary problems. That can be dealt with, but it seems more sensible to me to avoid the risk. Your vision of the future must begin with the children we seek to educate."

Thank God my bullshit reflex is still working. Given enough time, Severus could argue that up was down and black was white; his eloquence was one of his greatest strengths. What he had just said had been a load of complete crap, but he had included enough key words that – with luck – the Dark Lord would respond by letting him go on ahead; he needed just enough time to give a warning.

Voldemort traced what remained of his thin lips with a pointed nail, considering, watching him thoughtfully – thoughtfully, but mercifully not suspiciously. His gaze swept the table. "Are you all in agreement?"

Severus breathed out; if it went to a vote, he was safe. Unpopular though he was, there were a lot of people here with sons and daughters in Slytherin, and one or two in other houses; nobody, not even Death Eaters, wanted their children hurt. Besides, he had told the truth – there would be far less opposition to a takeover if the children were unharmed. A wave of cautious nods rippled around the table, and the Dark Lord nodded in turn.

"You can get the children out without the other staff noticing?"

"Yes," Severus lied calmly. He probably could hide it from anyone except Dumbledore, but he had absolutely no intention of trying. This was going to be bloody no matter what the final outcome was, and the children should be kept out of it.

"Very well, Severus. Go now. Be ready to act with us tonight; the time for secrecy is past."

Standing, he bowed deeply. "As my lord commands." Go fuck yourself. Turning on his heel, he walked out at his usual brisk stride, neither hurrying nor hesitating even as another wave of cramps ripped through him.

---

The world spun crazily around Severus again as he Apparated to the well-worn spot beside the Hogwarts gates, but he didn't have time for dizziness and he turned his stagger into an awkward leap skywards, the wind rushing past his face and stinging his skin, making his eyes water. The hot summer night was a dark blur as he streaked towards the castle, his heart hammering against his ribs and his throat tight with panic; because now that push had come to shove, he was bloody terrified. And yet, a small detached part of him was wondering idly why these things always happened in June. It seemed very neat that all the confrontations took place right at the end of the last term of the school year, with minimum disruption.

His landing was one of the worst he had ever made, gravel spraying everywhere as he hit the drive running and ploughed over, skinning both his knees and the heels of both his hands in a way that he hadn't done since he was twelve. Scrambling up, he vaulted up the steps to the door and let himself in before forcing himself to slow to a brisk walk, gulping air and doing his best to act normally as he strode towards the staff room and ignored the fear pounding in his brain.

It was early enough in the evening still that all of them were still present. Where had the time gone? It seemed like years had passed in the last couple of hours. Vaguely aware that the potion was still affecting him, screams still echoing in his head as the pain throbbed somewhere deep, he cleared his throat to attract his colleagues' attention and spoke quietly and clearly. "Minerva, Filius, Pomona, Horace." The four Heads of House, now; with the use of Slughorn's name he'd given the older man back the fortunes of Slytherin House. No choice; he wasn't going to be any good to them after tonight, and they hadn't been his for a long time now. As the four looked at him, he glanced from one to the other and said crisply, "The Blitz."

That code word had been his idea, as had quite a lot of the Order's secret phrases. The benefits of being a half-blood in touch with his Muggle side; he knew things nobody else in the group would understand. He doubted any of the four white-faced men and women staring at him now knew why the Blitz was the order to evacuate; the Second World War had been a Muggle affair and the wizarding world had largely kept out of it. It didn't matter; they knew what the code meant even if they didn't know why.

"Severus, are you sure?" Minerva asked faintly. "Where is Albus?"

He shook his head. "On his way back. There's no time, Minerva. Do it." Whirling on his heel, he stalked out and closed the door behind him and promptly ducked into the closest secret passage, wincing as his arm burned again; not directed at him, not now. Voldemort was gathering the others; time was running out.

As the school erupted into very tightly controlled chaos – they'd had the evacuation plans worked out for months – Severus found a quiet corner and tried with everything he had to summon his Patronus. Minerva would send word to Headquarters and muster the Order, but she wouldn't realise that Dumbledore had no bloody clue what was happening. The memory that sprang to mind was of the Room of Requirement, inevitably; the resulting silver fire was bright enough to all but blind him, brighter than it had ever been, but the damned thing still wouldn't take solid form. Whatever the new shape was going to become eventually, he was reasonably sure that it would still have four legs, but there was nothing of the doe left in the silver haze now; the glimpse of cohesion seemed to be something smaller, although at least it looked a bit larger than an otter. He stared at the amorphous swirl in frustration and swore at it, although why he had expected that to help was anyone's guess, before flicking his wand and letting it fade.

He had to warn them before they got back to the castle. The evacuation was well under way; everyone else was busy, and he didn't dare risk waiting by the gates because the Death Eaters might well arrive before them. His mind raced before a frantic idea struck him and he broke into a sprint through the castle, tearing along the corridors, skidding around corners and leaping up the staircases three or four stairs at a time.

By the time he burst into the open air on top of the Astronomy Tower, his lungs were burning and his knees and the muscles of his thighs were killing him, but he was reasonably certain that nobody had covered the distance so fast before. They probably hadn't had his motivation. Gasping for breath, he steadied himself against the battlement and yanked his sleeve back to expose the Dark Mark, black and vividly clear against the pale skin of his forearm. Drawing his wand, he held it carefully, the tip protruding between his fingers while the rest of it lay against his palm and wrist and extended down his arm, the very end of the wood resting against the Mark itself; blinking sweat out of his eyes, he raised his arm skywards, staring up at the stars.

"Morsmordre," he whispered, shuddering as the magic flared and writhed before a single green spark leaped from his wand tip. He tried to track it with his eyes as though it were a firework about to explode, but lost it among the stars until a moment later sickly green light flooded the world as the snake and skull formed above the tower.

It was the best he could do. Dumbledore and the Trio would see it as soon as they arrived at the school gates, and folk down in Hogsmeade would notice it as well and raise the alarm. Voldemort's attack wasn't going to be as stealthy as he had wished. Without more time, there was nothing else he could do.

Staring up at the symbol of everything he had once wanted and now opposed, Severus felt very small and very frightened, despite all his careful plans. It wasn't supposed to end like this. Taking a deep breath, he touched the scar ringing his right arm through his sleeve to try and give himself courage, trying not to think about what he was meant to do now. "May God have mercy on my soul," he whispered, closing his eyes for a moment before turning for the stairs and making his way back through the castle. There was no turning back now.

---

After Severus had left so unexpectedly, things had really gone to hell and the cave had become quite dramatic. By the time they had made it back to the school gates, Hermione had been numb, exhausted and shaken and worried about whatever Dumbledore wasn't saying; worry became full-blown panic when the Headmaster didn't seem surprised to see the Dark Mark looming above the castle. He refused to answer any of their questions as the four of them ran up the drive, except to say calmly that things would be all right if they had faith and kept clear heads and that no doubt their friends were safe.

She wasn't sure what to expect when the three of them nervously followed Dumbledore into the Great Hall; at least there were no signs of battle anywhere and the school seemed quiet. Evidently the Headmaster had been right when he had assured them that the teachers would have evacuated the students at the first hint of trouble. He clearly knew what was going on right now, which meant that Severus presumably knew as well, and hopefully others in the Order; Hermione tried to have faith in that and tried to stay calm.

The Great Hall was filled with people. Closest to the doors, the Order of the Phoenix stood in ranks, at least some of them; obviously not everyone had managed to get here in response to whoever had contacted them. Of the staff, only Professor McGonagall and Professor Flitwick were present, and Hagrid with Fang beside him. The Order were facing the other group of people in the Hall; rows of hooded and masked Death Eaters stood in silence on the other side of the room, with Voldemort at their head. The sight of him brought back all Hermione's old nightmares about the battle at the Ministry, but she was more concerned now with trying to find Severus. He wasn't standing with the Order, which was no surprise, but it was impossible to tell if he was one of the faceless people in black standing behind Voldemort. There were far more of them than she had ever dreamed there would be.

Some of the Death Eaters could be identified; Narcissa Malfoy and Bellatrix Lestrange were the only women, and Lucius Malfoy was standing beside his wife, recognisable by his cane. Fenrir Greyback too was easy enough to spot by the shaggy matted hair escaping from under his hood, and Crabbe and Goyle Senior could be guessed at from their size, but the others were all anonymous and unidentifiable. The only one without a mask apart from Voldemort himself was Draco, who was standing behind his parents and looked absolutely terrified.

"Ah, Dumbledore," Voldemort greeted them. He was actually smiling, which was one of the most horrible things she had ever seen, his slitted nostrils flaring and his red eyes gleaming. "So glad you could make it. I was afraid we would have to start without you. And you brought the Golden Trio with you, as well? Perfect."

Hermione missed whatever the Headmaster said in response as she scanned the Hall again. The Golden Trio had been Severus' nickname for them; her throat tightened painfully as she stared at the masked figures, trying to see if he was there. Everything had come to a head; what if Voldemort had decided that he didn't need Severus any more? He might already be dead for all she knew, especially since he had been in a bad way when he'd left them.

"I quite agree, Dumbledore," Voldemort said icily. "This has gone on long enough. I have had enough of games; let us settle this." He turned and looked back at the massed ranks of his followers. "Draco, step forward."

Draco already looked terrified, but now he went bloodlessly pale as he slowly left the shelter of his parents and ventured uncertainly out in front of the crowd, drawing his wand and clenching it in his fist as he stared at Dumbledore with too-wide eyes and tried to sneer.

"Oh God," Harry whispered from next to Hermione, swallowing. "Poor Malfoy... no wonder he was crying. I didn't realise he'd been asked to do this."

Hermione wasn't really paying much attention, still trying to find Severus with increasing panic. If this was what Draco was being forced to attempt... and Severus had sworn to help him... Oh, Christ...

The Headmaster sighed and smiled almost kindly at the terrified boy standing in front of him. "Really, Tom, you must realise I do not intend to allow the boy to go through with this. You've forced him this far. That's enough."

"Forced?" Voldemort repeated, smiling unpleasantly. "You continue to have faith in humanity, Dumbledore... can you not simply accept that not everyone likes you?" His voice hardened to a hiss. "Draco."

The younger Malfoy took a deep breath and raised his wand; his hand trembled for a moment, then steadied, and his expression cleared. Hermione recognised the signs; someone had taught him a bit of Occlumency. Severus? Maybe. Where was he?

Draco exhaled and started to speak, then froze, before his eyes closed and he slumped bonelessly to the floor. Someone had wandlessly and non-verbally sedated him; it hadn't been a Stunner, there had been no flash of red light. Dumbledore shook his head and smiled sadly. "Poor Draco. He couldn't have done it, you know. He is not a killer."

Two Death Eaters broke ranks silently, ignoring Voldemort's hiss of anger; Lucius and Narcissa, wordlessly walking forward in unison to lift their son and carry him out of the way. They fell back to their own lines, the black-clad masked figures parting briefly to let them pass and closing around them once more.

Dumbledore looked up with a cheerful smile. "So, Tom, what now?"

"The Dark Lord has planned for this, you old fool," Bellatrix declared; her high, breathy voice sounded just as it had in the Ministry, slightly laughing and completely mad. "My lord, this game has gone on long enough, surely. Let your spy prove his worth, as he swore to do. Draco is clearly unable to fulfil his duty..."

"Agreed," Voldemort said softly after a moment, his horrible smile returning as he glanced briefly to one side. "Come, my spy, it is time for you to proclaim your true allegiance at last..."

Hermione's heart turned over in her chest as a familiar deep silky voice replied quietly, "Yes, my lord," and one of the anonymous figures stepped forward. As soon as he moved, she knew him; nobody else had that liquid, deadly grace. Reaching up slowly, he pushed back his hood and removed his mask, and Severus Snape bowed to Voldemort before turning neutral black eyes to the Order. His face was as expressionless as ever, if a little paler than usual, his eyes cold and empty and guarded.

"Your friends do not seem pleased to see you, Severus," Voldemort noted in a mocking tone of voice.

"No, my lord," he agreed quietly, regarding them all without expression. "I did not expect them to be."

The Order were all staring at him, with fury, shock and betrayal raw and gleaming in every face, and for a moment Hermione wanted to scream at them. How many times had everyone misjudged him, and when had they ever been right? She had no idea what was going on at the moment, but she knew that Severus was no traitor. She hadn't been sure of him in the past either, she had doubted him as much as anyone, but she was sure now, even as he slowly walked across the floor towards them across the area of no-man's-land between the two factions. Unbreakable Vows and mysterious terrifying tasks were all very well, but obviously things weren't what they seemed.

"If anyone moves, you will all be slaughtered where you stand," Voldemort said lazily, watching Severus' progress with gleaming eyes; he was obviously enjoying this display of power. Only then did Hermione pay attention enough to realise that all the Death Eaters – including Severus – had their wands out, but the Order members did not. They were horribly outnumbered, she noticed uneasily, and hoped like hell that someone had a plan.

It seemed to take forever for Severus to walk across the relatively short distance, the tap of his boots the only sound, until he stood in front of Dumbledore and met the Headmaster's eyes stonily. Flicking his wand almost negligently, he said quietly, "Expelliarmus," and Hermione's heart turned to ice in her chest. She stared at him in disbelief as he plucked Dumbledore's wand out of the air and tucked it away somewhere inside his clothes. The Headmaster made no attempt to stop him, merely stood and met his eyes with a grave expression that wasn't remotely surprised.

"Get a move on, Snape," someone yelled from behind Voldemort. "Don't be so dramatic."

Voldemort smiled his horrible smile again; Severus' expression didn't alter by so much as a hair. "Yes, my spy – enjoyable though this is, we have much to do this night."

Sick with horror, Hermione watched numbly as Severus nodded and raised his wand. "As you wish, my lord." His expression still hadn't wavered; his eyes were hard and cold.

It was Hagrid who yelled in a choked voice, "Yeh're a bloody coward, Snape! An' a traitor!"

Severus didn't even blink. "Yes. I am that." His voice was very quiet indeed, and now for the first time Dumbledore wavered and looked a little afraid.

"Severus..." he said softly. "Please..."

Then, finally, Severus' blank expression altered; suddenly his eyes were burning with rage and hate as something snapped, and Hermione's throat closed as everything began to crash down around her. He was really going to do it... he was really going to betray them all, now, after – after everything that had happened... Her vision darkened at the edges, but she couldn't look away from the man she had kissed so desperately not that long ago, who had never been more of a stranger to her.

"Oh, Albus," Severus said almost gently, his soft voice at odds with the savage hate in his eyes. "Don't be such a bloody martyr."

He brought his wand down, and in one swift movement he amputated the Headmaster's right arm just above the elbow.