Sev automatically stumbled a few steps backwards. Impassive or not, there was something utterly instinctual about recoiling from a skeleton.

Once automatic reaction was done, cool reflection kicked right back in. It was a skeleton; it was far beyond any help he could have provided, and there was no reason to be afraid of it. He took a closer look.

He tried to judge how long the bones might have lain there. They could have been picked clean by scavengers, but there were also remnants of clothes, and they were rotting. Sev was no expert on decomposition, but common sense could still guide him. In the damp atmosphere of the forest, this body had probably been here somewhere between a matter of months and a few years.

It was hard to tell anything from what was left of the clothing; it looked to have been a dark-coloured robe, but what did that prove on Hogwarts grounds?

The bones had been somewhat scattered; perhaps by animals, perhaps partly from when he - and presumably Lewis - had stumbled over it. Even so, he could glean some sort of rough idea of the size of the skeleton, and he didn't think it had been a child; not a young one, anyway.

Snape stepped closer, as his magical light glinted off something metallic on the ground. He knelt down, ignoring the slightly spongy ground as mud soaked into his robe, and picked it up.

It was a small golden earring, twisted into an elaborate coil. A cursory inspection of the ground found its twin. After all, the skull no longer had ears to hold them in.

Sev held the pair of them in his palms and studied them thoughtfully. They were familiar... He closed his eyes, and allowed his mind to flood back; back over a thousand vividly stored memories, snapshots of his life.

The right one slotted into place, and his eyes snapped open. Yes, he had seen these earrings before... last year in fact. In his astronomy classes.

He looked at the skeleton again, but it was still just bones. The knowledge hadn't changed it. Even knowing that this was her corpse, he couldn't see anything of Professor Cephus in it.

The mystery of her absence was no longer so mysterious. How long had she lain dead here? Since the start of this school year, or the end of the last?

He briefly pondered how she had ended up in the Forbidden Forest, but dismissed it as useless. There were too many ways she could have been lured out here, and there was no proof that this was even where she'd died.

The silent bones offered no clue as to how it might have happened, so he started to comb over the immediate area. Perhaps there was no reason to expect to find anything, and yet...

It was something about the way the body had been dumped that bothered him. The... incompleteness... of it. If you had gone to the trouble of hauling the body out to the Forbidden Forest, why not drag it deeper inside? Why not bury it, or cast some subtle masking spell?

And that, naturally, led to the conclusion that it hadn't truly been meant to be hidden. Whoever had dumped it had wanted it to be found... just not immediately.

The killer didn't want their actions to be known, but they wanted the result of them to be. A message was being sent. And somebody who wanted to send this kind of message wouldn't take the risk of it being missed or misunderstood.

He found the note pinned to a nearby tree. It was a rolled up scroll, held shut by a rusted nail through the bottom. Sev took the nail-head in his fingertips and pulled it free. The scroll flapped open.

The words were written in an ornate, cursive script. Sev wouldn't have been incredibly surprised if the ink it was written in turned out to be blood - although he would have betted that if it was, it wouldn't be the author's. This was not a furtively scribbled note, but a carefully planned missive. Somebody was showing off their sense of drama.

It was difficult to read by the light of his wand, and he leaned in closely. The note read; The blood of wizardry has been diluted. We will suffer these wretched half-breeds no more. Signed: the Brotherhood of the Death Eaters.

The name was unfamiliar to him. Next to the final 's' was what looked like a dark blot on the paper. Sev placed a hand behind the note to pull it closer to his eyes, and then leapt back as green light flared. Reflexes had him halfway across the clearing, wand out, before he recognised that this spell was not a magical boobytrap.

The tiny star of sparkling green that drifted outwards and upwards seemed utterly incongruous - like a fairy light or a fragment of a firework. Then, as Sev watched, it split in half and in half again. The lights multiplied rapidly, forming a globe of dancing lights several feet across, easily visible against the black of the night sky.

The lights swarmed around each other like miniature fairies. They bunched together, and then spread out again, taking on a new shape. Before his eyes, they formed into an obscenely grinning skull, hugely and distorted with a snaking tongue. In one of the eyesockets the lights flared in a supernova wink.

Sev waited for the lights to dissipate, but they merely hung there. Even if Lewis hadn't gone dashing straight back up to the school to find the headmaster, it wouldn't be long before somebody noticed the unholy light display.

He still had his invisibility cloak, though he had tugged it off to move more easily amongst the trees. Now he slid back under it, and sat quietly on a treestump to wait.

The huge magical skull high above bothered him far more than the real one lying inches from his feet.

He heard the voices of the searchers long before they appeared in the clearing. Malachite and Dumbledore; they had come alone, and come quickly. No doubt the enormous hovering skull had convinced them more powerfully than any wild story of Lewis's.

Professor Malachite sounded angry, and somewhat out of breath. "I'm telling you, Albus, it's a prank. I'll bet it's that Potter boy again. Ellida lets him and Black get away with murder."

"The same could be said for some of your house, Carnus," Dumbledore pointed out mildly. His voice carried through the silence of the night, but Sev didn't think he was too far away. He had of course extinguished his magical light, and the two teachers had a fair amount of ground to search even with the skull as a rough guide.

"I should think, with everything that's going on," Malachite observed bitterly, "people should see that my house are very much the victims here. But no; whenever house Slytherin is involved, all the old prejudices come out."

"It can be easy to fall into that trap," Dumbledore acknowledged. His voice sounded further away now; he was somewhere off to Sev's right. "And it can be easy to fall too far out of it."

"What's that supposed to mean?" he asked, sounding both irritated and confused. "You talk in riddles, old friend."

"Don't be blinded," Professor Dumbledore cautioned him. "Others see nothing because of their prejudices, but you see just as little when you're so defiant of them."

There was a brief silence, and then Malachite said sharply "This is about Malfoy, isn't it?"

Sev could picture the headmaster's expression - that gentle little upwards flick of his eyebrows that let you know your words were foolish, but he was going to let you dig your own grave anyway. "I merely warned that it might be wise to take a closer look at his activities."

"Well, I've looked, and I see nothing to be bothered by!" the Dark Arts professor snapped. "Lucius Malfoy has the potential to be a great wizard!"

"With that, I won't argue," said Dumbledore mildly. "But you should remember that there's a difference between a great wizard and a good wizard."

Malachite grumbled something inaudible. His voice grew louder as the two searchers turned back towards the clearing. "Why is it always Malfoy with you? He's far from the only mystery in house Slytherin. Take Severus, if you will."

Dumbledore made an acknowledging sound that might have been agreement.

"I mean, I don't know what's wrong with the boy," Malachite said, half to himself. "He's so bright! But he won't let anyone near him. Lord knows I've tried to get him interested in things, tried to get him to open up, but he just doesn't seem to see what I'm doing."

"Oh, he sees more than you give him credit for," Dumbledore said quietly.

Malachite made an exasperated 'ha!' sound. "See, this is how it always is with you, Albus. You think you know these students better than they know themselves. Well, sometimes, you know, what's on the surface is exactly what's underneath. You're seeing things that just aren't there."

"No," the headmaster corrected gently. "I'm just seeing things that are really there. You'd be amazed how few people know how to do that."

Sev never got to hear Malachite's response to that, because at that point he stumbled across the clearing. He swept his lit wand out in a cursory inspection, and then froze. "Albus!" he called urgently.

The teacher moved gingerly towards the skeleton, and stood looking down at it. In the shadows, his expression was unreadable.

Dumbledore emerged from the trees to stand beside him. He didn't look shocked so much as gently sorrowful, as if this had been what he was expecting.

"Well, it appears young Lewis was less disturbed than you all seemed to think," he observed quietly. He looked up, at the still-hovering skull. It had been there near a half-hour now, but the light had not begun to fade. "And this, my friend, is anything but a prank," he added darkly.

Malachite's attention was still focused on the skeleton. "Who is it, do you think?" he asked.

Dumbledore's expression melted back into sorrow. "That, Carnus, I can tell you. Dear Auriga; what could such a gentle soul have done to deserve this?"

Malachite started in shock and took an involuntary step backwards. He seemed genuinely startled for the first time. "Wha- How can you know?"

"I had my suspicions as soon as Lewis Matthews came charging into my office," he said. He stepped forwards, and picked up one of the ornate earrings from where Sev had replaced it. "And this only confirms them," he added softly.

"Auriga Cephus," said Malachite, and he closed his eyes. He rubbed at his chest nervously, as if he was suddenly having difficulty taking breath.

Dumbledore's sharp eyes had spotted the note Sev had untacked on the tree-trunk. He moved over and pulled it free. "Well, our culprits have identified themselves," he said, showing it to Malachite.

"Death Eaters?" The Dark Arts teacher clutched his arms up against his chest, as if hugging himself against a sudden chill.

"A name I've heard before..." Dumbledore admitted darkly.

"Before?" asked the other man nervously.

Dumbledore nodded slowly. "There have been rumours of a growing organisation for some time now. I have friends amongst the Aurors; they send me news of what's going on at the edges of society. A few times now I've heard mention of these Death Eaters. One of my correspondents spoke of a 'mark' they displayed over the scenes of their crimes." He shot a dark look at the hanging skull. "Now I know what he meant."

He scowled down at the piece of paper, then produced his wand from the inside of his robes. He whipped it towards the dark blot on the page and snapped "Deletrius!" The skull shrank down to a single point, and then melted back into the paper.

Dumbledore crumpled it, and thrust it inside his robe with the wand. "Come, Carnus," he said, his face falling into stern lines. "The Ministry must be notified."

Sev followed them back to the school.

The team of specialists from the Ministry appeared rapidly, and with minimum fanfare. Even Sev's invisibility cloak wouldn't get him inside their meeting; they set numerous wards and detectors outside the door of the headmaster's office.

However, he didn't really need to be inside to know what went on. The men from the Ministry went out to the forest and quietly retrieved the skeleton. Sev suspected they took the note, as well, and from the thundery look on Dumbledore's face he knew they'd ordered the headmaster to keep silent about it. It was just like the Ministry to 'not want to alarm people', but that had never been Dumbledore's way. He believed that however young they were, his students had a right to know the truth of what was going on.

Dumbledore had the Ministry men do one more thing before they departed; Sev followed them down to the infirmary and watched as they set up powerful anti-darkness wards around Josh Matthews's bed.

The following Friday, the headmaster called the school together for a special assembly. It was a much graver affair than most such gatherings; everyone had heard about Josh, and the rumour of the mysterious skull in the night had been spreading around.

When Dumbledore stood, there was little trace of his customary twinkle on display. "I have grave tidings on two counts," he said without preamble.

"I regret to inform those of you who remember her from last year that Professor Auriga Cephus is no longer among the living." The ripple of dismay that spread through the crowd was subdued; it had been nearly a full year now, and old teachers quickly faded out of students' memories. "Professors Alomanicia and Melusine will continue to cover her classes until we can appoint a replacement next year." He paused briefly.

"You have all, no doubt, heard about the unprecedented attack on one of our number: Joshua Matthews." Most people's eyes flickered guiltily over to Lewis; Sev's went straight to Malfoy. He was gazing up at Dumbledore with an innocently curious expression. "It is a dark time when even students have to guard themselves against magical attacks; but it seems these are dark days indeed. I do not believe anything like this is likely to happen again on Hogwarts grounds in the near future, but I would ask you all to be on your guard. If you see anything suspicious, I would ask you to come and see me or your head of house immediately. Perhaps a little paranoia is justified, in days such as this."

A murmur of disquiet travelled through the room.

Finally, Dumbledore broke into a smile. "However, I now have some much better news on that front. Madame Florence informs me that the treatments she has been trying are now beginning to have some success, and she's fully confident that Josh will awake from his coma in a matter of days."

The relieved applause that exploded across the room was louder nowhere than at the Slytherin table. Perhaps only Sev knew that what they were really applauding was the lessening of the weight of their own guilt.

Sev was there when Josh awoke. He waited until Madame Florence chased out his weeping parents and overexcited brother to sweep off the invisibility cloak and reveal himself.

Josh didn't seem surprised to see him. He smiled humourlessly, and said "I thought you'd be here."

This was the time, if there was a time, for heartfelt apologies and confessions. But Josh wouldn't want to hear them, and Sev wouldn't know how to give them. He just nodded in acknowledgement.

"You're leaving," he stated. It wasn't a question, but Josh nodded anyway.

"Mother thinks it's time Lewis and I went into private tuition. She always talked about us doing that anyway, but..." he closed his eyes briefly "I wanted to go to a proper school. Well, now we've had the Hogwarts experience." He gave another bitter smile. "Wouldn't have missed it for the world," he said wryly.

"They asked you who did it?"

"And I said I didn't know," Josh confirmed. He shrugged. "It wouldn't make any difference anyway." He looked up at Sev. "You were right. I didn't want to believe you, but you were right." He laughed quietly to himself. "It doesn't work if you fight. It doesn't really make any difference."

He fell silent for a long time, looking at the curtains. Then he straightened up in bed and met Sev's eyes again. "Lewis and me, we're getting out while we can," he said. He gave Sev an unreadable look. "Maybe you should do the same."

"I'm not trying to get out, I'm trying to get in," he pointed out quietly.

Josh nodded slowly. "Good luck," he said, with a half-shrug. His face tightened. "I think you're gonna need it."

The Matthews family packed up and left the next day. Malfoy and his cronies were loudly triumphantly, but their glee rang hollowly in the suddenly oppressive common room. The other Slytherins didn't seem to want to meet each other's eyes anymore.

The departure of Lewis and Josh sent ripples of disquiet through the whole school. Even those who hadn't known them were disheartened by their leaving, and the atmosphere in Hogwarts was changing. The teachers, Dumbledore most of all, began to look stern and worried. People were beginning to be afraid.

Even the train ride home for the summer vacation had little of its customary jubilation. Sev suspected that Josh and Lewis were not the only ones who would not return next year. The fabled Hogwarts had lost some of its air of safety, and everyone was feeling the aftereffects of that loss of innocence.

Sev, however, hadn't had much innocence to begin with, and there were other, far more concrete matters to worry over. Malfoy had revealed much more of his dark side and some of his newly-gained power, but Sev still was no closer to discovering his mysterious allies.

Even more troubling was that note left with Professor Cephus's body. The choice of Josh as Malfoy's victim had been near arbitrary; pure schoolboy spite. Josh had been a random victim; what happened when it was somebody Malfoy had a true vendetta against?

As the train pulled into the London station, Sev happened to glance across at the next carriage and see Lily and her friends tumble out. They had regained something of their sense of fun, and were cheerfully bidding each other goodbye.

Seeing Lily laughing with her friends like that made him feel a sudden pang of some melancholy he couldn't quite identify. He scrabbled in his bag, and pulled out the invisibility cloak. Then he took out a scrap of parchment, and scribbled out a few brief words.

In the crush of the station, he managed to brush by her, and slip the cloak into her school bag, with the note tightly wrapped up in its centre.

Be careful, and take this. I think you might need it.