May 13th, 1992.

Argus Filch's face appeared twisted in the light of the oil lamp he held, shadows dancing over his face. Behind them the doors of Hogwarts quickly receded, and the dark grounds moved closer. The track they now walked was muddy and indistinct.

The trees, branches formerly bare with winter, were not yet fully clad with spring; their branches stretched up toward the sky like lean fingers, skeletons visible amid the thin foliage. The moon was bright, but clouds scudding across it often threw them into darkness, lit only by the dim flames of Filch's lamp.

Draco kept a firm grip on his wand.

"Where are you taking us?" said Tracey Davis. She'd been caught along with Draco by Filch, on their way to an attempted meeting of the Silvery Slytherins after curfew hours, and likewise given a detention.

"You just follow me," said Argus Filch.

Draco was feeling rather annoyed with the whole affair. The Silvery Slytherins ought to be recognized school business. There was no reason why a secret conspiracy shouldn't have permission to meet after curfew, if it was for the greater good of Hogwarts. If this happened one more time he'd talk to Daphne Greengrass and Daphne would talk to her father and then Filch would learn the wisdom of looking the other way where Malfoys were concerned.

The lights of the Hogwarts castle had diminished in the distance when Filch spoke again. "I bet you'll think twice about breaking a school rule again, won't you, eh?" Filch turned his head, away from the lamp, so that he could leer at the four students following him. "Oh yes... hard work and pain are the best teachers if you ask me... It's just a pity they let the old punishments die out... hang you by your wrists from the ceiling for a few days, I've got the chains still in my office, keep 'em well oiled in case they're ever needed..."

"Hey!" Tracey said, a touch of indignation entering her voice. "I'm too young to hear about that - that sort of - you know! Especially if the chains are well-oiled!"

Draco wasn't paying attention. Filch simply wasn't in Amycus Carrow's league.

Behind them, one of the two older Slytherins following them snickered, though she didn't say anything. Beside her was the other, a tall boy with an Slavic cast to his face, and who still spoke with an accent. They'd been caught for some unrelated offense, having to do with the type of thing Tracey went on about, and looked to be in their third or fourth year. "Pfeh," said the taller boy. "In Durmstrang they hang you upside-down by your toes. By one toe, if you are insolent. Hogwarts was soft even in the old days."

Argus Filch was silent for around half a minute, as though trying to think of a proper rejoinder, and then gave a chuckle. "We'll see what you say about that... when you learn what you'll be doing tonight! Ha!"

"I said, I'm too young for that sort of thing!" said Tracey Davis. "It has to wait until I'm older!"

Ahead of them was a cottage with lighted windows, though the proportions seemed wrong.

Filch whistled, a high sharp sound, and a dog began barking.

From the cottage stepped forth a figure, making the trees seem too short around it. The figure was followed by a dog that seemed like a puppy by comparison, until you looked at it apart from the taller silhouette and realized the dog was huge, more like a wolf.

Draco's eyes narrowed, before he caught himself. As a Silvery Slytherin he wasn't supposed to be Prejudiced against any sentient being, especially not where other people might see him.

"What's this?" said the figure, in the loud gruff voice of the half-giant. His umbrella lit up with a white glow, brighter than Filch's dim lamp. In his other hand he held a crossbow; a quiver of short bolts was strapped to his upper arm.

"Students serving detention," Filch said, loudly. "They're to help you search the Forest for… whatever's been eating 'em."

"The Forest?" gasped Tracey. "We can't go in there at night!"

"That's right," said Filch, turning from Hagrid to glare at them. "It's into the Forest you're going, and I'm much mistaken if you'll all come out in one piece."

"But -" said Tracey. "There's werewolves, I've heard, and vampires, and everyone knows what happens when there's a girl and a werewolf and a vampire all at the same time!"

The huge half-giant was frowning. "Argus, I 'ad in mind you an' maybe a few seventh-years. 'Ere's not much point in bringing along help if I'm to watch over 'em the whole time."

Argus's face lit with cruel satisfaction. "That's their lookout, isn't it? Should've thought of them werewolves before they got in trouble, shouldn't they? Send them out alone. I shouldn't be too friendly to them, Hagrid. They're here to be punished, after all."

The half-giant gave a massive sigh (it sounded like a normal man having all the air driven out of his lungs by a Bludgeoning Hex). "Yeh've done yer bit. I'll take over from here."

"I'll be back at dawn," said Filch, "for what's left of them," he added nastily, and he turned and started back toward the castle, his lamp bobbing away in the darkness.

"Right then," said Hagrid, "now, listen carefully, 'cause it's dangerous what we're gonna do tonight an' I don' want no one takin' risks. Follow me over here a moment."

He led them to the very edge of the Forest. Holding his lamp up high he pointed down a narrow, winding earth track that disappeared into the thick black trees. A light breeze blew over Draco's head as he looked into the Forest.

"There's summat in there that's bin eatin' unicorns," the huge man said.

Draco nodded; he distantly remembered hearing something along those lines a couple of weeks ago, toward the end of April.

"Did you call us to track down a trail of silvery blood to a wounded unicorn?" Tracey said excitedly.

"No," said Draco, though he managed to stop the reflexive sneer. "Filch gave us the detention note at lunch today, at noon. Mr. Hagrid wouldn't wait that long to find a wounded unicorn, and if we were looking for something like that, we'd look in the day when it's bright. So," Draco held up a finger, like he'd seen Inspector León do in plays, "I infer that we're looking for something that only comes out at night."

"Aye," said the half-giant, sounding thoughtful. "Yer not what I expected, Draco Malfoy. Not what I expected at all. An' you'd be Tracey Davis, then. I've heard of yeh. One of poor Miss Granger's lot." Rubeus Hagrid looked over at the two older Slytherins, peering at them in the light of his glowing umbrella. "An' who'd yeh be, again? Don't remember seeing much of yeh, boy."

"Cornelia Walt," said the witch, "and this is Yuri Yuliy," indicating the Slavic-looking boy who'd spoken of Durmstrang. "His family is visiting from the Ukrainian lands, so he's in Hogwarts just for the year." The older boy nodded, a faintly contemptuous cast on his face.

"This is Fang," Hagrid said, indicating the dog.

The five of them set off into the woods.

"What could be killing unicorns?" Draco said after they'd walked for a few minutes. Draco knew a bit about Dark creatures, but he couldn't remember anything that was said to prey on unicorns. "What sort of creature does that, does anyone know?"

"Werewolves!" said Tracey.

"Miss Davis?" Draco said, and when she looked at him, he silently pointed a finger up at the moon. It was waxing gibbous, but not yet full.

"Oh, right," said Tracey.

"No weres in the Forest," said Hagrid. "They're plain wizards most o' the time, 'member. Couldn't be wolves either, they're not near fast enough ter catch a unicorn. Powerful magical creatures, unicorns are, I never knew one ter be hurt before."

Draco listened to this, thinking about the puzzle almost despite himself. "Then what is fast enough to catch a unicorn?"

"Wouldn't 'ave been a matter of speed," Hagrid said, giving Draco an indecipherable glance. "Ere's no end ter the ways that creatures hunt. Poison, darkness, traps. Imps as can't be seen or heard or remembered, even while they're eatin' yer face. Always summat new an' wonderful to learn."

A cloud passed over the moon, casting the forest into shadow lit only by the glow of Hagrid's umbrella.

"Meself," Hagrid continued, "I think we might 'ave a Parisian hydra on our 'ands. They're no threat to a wizard, yeh've just got to keep holdin' 'em off long enough, and there's no way yeh can lose. I mean literally no way yeh can lose so long's yeh keep fightin'. Trouble is, against a Parisian hydra, most creatures give up long before. Takes a while to cut down all the heads, yeh see."

"Bah," said the foreign boy. "In Durmstrang we learn to fight Buchholz hydra. Unimaginably more tedious to fight! I mean literally, cannot imagine. First-years not believe us when we tell them winning is possible! Instructor must give second order, iterate until they comprehend."

They walked for nearly half an hour, deeper and deeper into the Forest, until the path became almost impossible to follow because the trees were so thick.

Then Draco saw it, thick splashes on the roots of trees, gleaming a brighter color beneath the moonlight. "Is that -"

"Unicorn's blood," Hagrid said. The huge man's voice was sad.

In a clearing ahead, visible through the tangled branches of a great oak, they saw the fallen creature, splayed beautiful and sad upon the ground, the dirt around her shining moon-silver with pooled blood. The unicorn was not white, but pale blue, or appearing so beneath the moon and night sky. Her slender legs stuck out at odd angles, obviously broken, and her mane spread across the dark leaves, green-black but with a sheen like pearls. On her flank was a small white shape like a starburst, a center surrounded by eight straight rays. Half her side had been ripped away, the edges ragged like the marks of teeth, bones and inner organs exposed.

A strange choking sensation rose in Draco's throat.

"That's 'er," Hagrid said, his sad whisper as loud as a normal man's voice. "Just where I found 'er this mornin', dead as a dead doorknob. She is - was - the first unicorn I e'er met in these woods. I called 'er Alicorn, not that it matters ter 'er any more, I s'pose."

"You named a unicorn Alicorn," said the older girl. Her voice was a bit dry.

"But she doesn't have wings," Tracey said.

"An alicorn's a unicorn's horn," Hagrid said, now louder. "Don't know where yeh all started thinking it meant a unicorn with wings, 'ere's no such thing I ever heard. It's just like naming a dog Fang," indicating the huge wolf-like dog that barely came to his knees. "What'd you have called 'er? Hannah, or some such? I gave 'er a name as would've meant summat ter 'er. Common courtesy, I call it."

Nobody said anything to this, and after a further moment, the huge man gave a sharp nod. "We'll start our search from 'ere, the last place it struck. We're gonna split inter two parties an' follow the trail in diff'rent directions. Yeh two, Walt and Yuliy - yeh'll go that way, and take Fang. There's nothin' that lives in the Forest that'll hurt yeh if yer with Fang. Send up green sparks if yeh find summat interestin', an' send up red sparks if anyone gets in trouble. Davis, Malfoy, with me."

The Forest was black and silent. Rubeus Hagrid had dimmed the light of his umbrella after they'd set out, so that Draco and Tracey had to steer themselves by the light of the moon, not without occasional trips and falls. They walked past a mossy tree-stump, the sound of running water speaking of a stream somewhere close by. Now and then a ray of moonlight through the branches above lit a spot of silver blue blood on the fallen leaves; they were following the trail of blood, toward where the creature must have first struck the unicorn.

"There's rumors about yeh," Hagrid said in a low voice after they'd walked for a while.

"Well, they're all true," Tracey said. "All of them."

"Not yeh," Hagrid said. "Did yeh really testify under Veritaserum that yeh tried to help Miss Granger, three times it was?"

Draco weighed his words for a while, and finally said, "Yes." It wouldn't have done to appear too eager to claim credit.

The huge man shook his head, his great feet still stomping silently through the woods. "I'm surprised, teh be honest. And yeh too, Davis, tryin' to put the halls in order. Are yeh sure the Sorting Hat put yeh in the right place? There's not a single witch or wizard who went bad who wasn't in Slytherin, so it's always been said."

"That's not true," Tracey said. "What about Xiaonan Tong the Black Raven, Spencer of the Hill, and Mister Kayvon?"

"Who?" said Hagrid.

"Just some of the best Dark Wizards from the last two centuries," Tracey said. "They're probably the best from Hogwarts who weren't from Slytherin." Her voice fell, lost its enthusiasm. "Miss Granger always told me I should read up on anything I -"

"Anyway," Draco said quickly, "that's not really relevant, Mr. Hagrid. Even if -" Draco worked it around in his head, trying to translate the difference between probability of Slytherin given Dark and probability of Dark given Slytherin into nonscientific language. "Even if most Dark Wizards are from Slytherin, very few Slytherins are Dark Wizards. There aren't all that many Dark Wizards, so not all Slytherins can be one." Or as Father had said, while any Malfoy should certainly know much of the secret lore, the more... costly rituals were better left to useful fools like Amycus Carrow.

"So yeh're saying," Hagrid said, "that most Dark Wizards are Slytherins... but..."

"But most Slytherins are not Dark Wizards," Draco said. He had a weary feeling they'd be at this a while, but like fighting a hydra, the important thing was to not give up.

"I never thought of it that way," the huge man said, sounding awestruck. "But, well, if yeh're not all a house of snakes, then why - get behind that tree!"

Hagrid seized Draco and Tracey and hoisted them off the path behind a towering oak. He pulled out a bolt and fitted it into his crossbow, raising it, ready to fire. The three of them listened. Something was slithering over dead leaves nearby: it sounded like a cloak trailing along the ground. Hagrid was squinting up the dark path, but after a few seconds, the sound faded away.

"I knew it," Hagrid murmured. "There's summat in here that shouldn' be."

They went after where the rustling sound had come from, with Hagrid in the lead and Tracey and Draco both gripping their wands at the ready, but they found nothing, despite searching in a widening circle with their ears straining for the faintest sound.

They walked on through the dense, dark trees. Draco kept looking over his shoulder, a feeling nagging at him that they were being watched. They had just passed a bend in the path when Tracey yelled and pointed.

In the distance, a shower of red sparks lit the air.

"You two wait here!" Hagrid shouted. "Stay where yeh are, I'll come back for yeh!"

Before Draco could say a word, Hagrid spun and crashed away through the undergrowth.

Draco and Tracey stood looking at each other, until they heard nothing but the rustling of leaves around them. Tracey looked scared, but trying to hide it. Draco was feeling more annoyed than anything else. Apparently Rubeus Hagrid, when he had formed his plans for tonight, had not spent even five seconds visualizing the consequences if something actually went wrong.

"Now what?" said Tracey, her voice a little high.

"We wait for Mr. Hagrid to come back."

The minutes dragged by. Draco's ears seemed sharper than usual, picking up every sigh of the wind, every cracking twig. Tracey kept looking up at the moon, as though to reassure herself that it wasn't full yet.

"I'm -" Tracey whispered. "I'm getting a little nervous, Mr. Malfoy."

Draco thought about it a bit. To be honest, there was something... well, it wasn't that he was a coward, or even that he was scared. But there had been a murder at Hogwarts and if he'd been watching himself in a play, having just been abandoned in the Forbidden Forest by a half-giant, he would currently feel like yelling at the boy on stage that he should...

Draco reached into his robes, and took out a mirror. Tapping the surface showed a man in red robes, who frowned almost immediately.

"Auror Captain Eneasz Brodski," the man said clearly, causing Tracey to start with the loudness in the quiet forest. "What is it, Draco Malfoy?"

"Put me on ten-minute check-in," Draco said. He'd decided not to complain directly about his detention. He did not want to look like a spoiled brat. "If I don't respond, come get me. I'm in the Forbidden Forest."

Inside the mirror, the Auror's brows rose. "What are you doing in the Forbidden Forest, Mr. Malfoy?"

"Looking for the unicorn-eater with Mr. Hagrid," Draco said, and tapped the mirror off, putting it back in his robes before the Auror could ask anything about detentions or say anything about serving it out without complaining.

Tracey's head turned toward him, though it was a little too dim to read her expression. "Um, thanks," she whispered.

The few leaves which had emerged on their branches rustled as another, colder breeze blew through the forest.

Tracey's voice was a little louder when she spoke again. "You didn't have to -" she said, now sounding a little shy.

"Don't mention it, Miss Davis."

The dark silhouette of Tracey put her hand to her cheek, as though to conceal a blush that wasn't visible anyway. "I mean, not for me -"

"No, really," Draco said. "Don't mention it. At all." He would have threatened to take out the mirror and order Captain Brodski not to rescue her, but he was afraid she would consider that flirting.

Tracey's silhouetted head turned from him, looked away. Finally she said, in a smaller voice, "It's too soon, isn't it -"

A high scream echoed through the woods, a not-quite-human sound, the scream of something like a horse; and Tracey shrieked and ran.

"No, you numbskull!" yelled Draco, plunging after her. The sound had been so eerie that Draco wasn't certain where it came from - but he thought that Tracey Davis might, in fact, be running straight toward the source of that eerie scream.

Brambles whipped at Draco's eyes, he had to keep one hand in front of his face to shield them, trying not to lose track of Tracey because it seemed obvious that, if this was a play, and they got separated, one of them was going to die. Draco thought of the mirror secured within his robes but he somehow knew that if he tried to take it out one-handed while running, the mirror would inevitably fall and be lost -

Ahead of them, Tracey had stopped, and Draco felt relieved for an instant, before he saw.

Another unicorn lay on the ground, surrounded by a slowly widening pool of silver blood, the edge of the blood creeping across the ground like spilled mercury. Her coat was purple, like the color of the night sky, her horn exactly the same twilight color as her skin, her visible flank marked by a pink star-blotch surrounded by white patches. The sight tore at Draco's heart, even more than the other unicorn because this one's eyes were staring glassily right at him, and because there was a -

- blurring, twisting form -

- feeding on an open wound on the unicorn's side, like it was drinking from it -

- Draco couldn't understand, somehow couldn't recognize what he was seeing -

- it was looking at them.

The blurring, seething, unrecognizable darkness seemed to turn to regard them. A hiss came from it, like the hiss of the deadliest snake which ever had existed, something more dangerous by far than any Blue Krait.

Then it bent back over the wound in the unicorn, and continued to drink.

The mirror was in Draco's hand, and it remained lifeless as his finger mechanically tapped at the surface, over and over.

Tracey was holding her wand now, saying things like "Prismatis" and "Stupefy" but nothing was happening.

Then the seething outline rose up, like a man rising to his feet only not so; and it seemed to scuttle forward, moving with a strange half-jump across the dying unicorn's legs, approaching the two of them.

Tracey tugged at his sleeve and then turned to run, run from something that could hunt down unicorns. Before she could take three steps there came another terrible hiss, burning his ears, and Tracey fell to the ground and did not move.

Somewhere in the back of his mind, Draco knew that he was about to die. Even if the Auror checked his mirror this very instant, there was no way anyone could get here fast enough. There was no time.

Running hadn't worked.

Magic hadn't worked.

The seething outline came closer, while Draco tried, in his last moments, to solve the riddle.

Then a blazing silver ball of light plunged out of the night sky and hung there, illuminating the forest as bright as daylight, and the seething outline leapt backwards, as though in horror of the light.

Four broomsticks plunged out of the sky, three Aurors with bright multicolored shields and Harry Potter holding his wand aloft, seated behind Professor McGonagall within a larger shield.

"Get out of here!" roared Professor McGonagall -

- an instant before the seething thing gave forth another terrible hiss, and all the shielding spells winked out. The three Aurors and Professor McGonagall fell off their broomsticks and dropped heavily to the forest floor, lying motionless.

Draco couldn't breathe, the most intense fear he'd ever felt in his life gripping all through his chest, sending tendrils around his heart.

Harry Potter, who had remained untouched, silently guided his broomstick toward the ground -

- and then leapt off to stand between Draco and the seething outline, interposing himself like a living shield.

"Run!" said Harry Potter, turning his head half-back to look at Draco. The silver moonlight gleamed on his face. "Run, Draco! I'll hold it off!"

"You can't fight that thing alone!" Draco cried aloud. A nausea was in his stomach, a churning sensation that, looking back in memory, seemed both like and unlike a sense of guilt, as though it had the sensations but not quite all of the emotion.

"I must," Harry Potter said grimly. "Go!"

"Harry, I - I'm sorry, for everything - I" Though later, looking back, Draco couldn't quite remember what he'd meant to apologize for, maybe it'd been that he was planning to overthow Harry's conspiracy, all that time ago.

The seething figure, now seeming blacker and more terrible, rose up into the air, hovering off the ground.

"GO!" shouted Harry.

Draco turned and fled headlong into the woods,with the branches whipping at his face. Behind him, Draco heard another terrible hiss, and Harry's voice rising, crying something that Draco couldn't make out from the distance; Draco turned his head for only an instant to look back, and in that moment ran into something, hitting his head HARD, and blacked out.

Harry held a tight grip on his wand, a Prismatic Sphere glowing around him. He stared levelly at the seething, blurring form in front of him, and said, "What on Earth are you doing?"

The seething blurs resolved, reformed, relaxed back into a hooded form. Whatever concealment had been at work - a device rather than a Charm, Harry guessed, since the magic had been able to affect him - had prevented his mind from recognizing the shape or even that the shape was human. But it hadn't prevented Harry from recognizing the sharp sense of doom.

Professor Quirrell stood straight with silver blood all down the front of his enshrouding black cloak, and gave a sigh, looking at the fallen forms of three Aurors, Tracey Davis, Draco Malfoy, and Professor McGonagall. "I had honestly thought," Professor Quirrell murmured, "that I jammed that mirror without alarm. What were two first-year Slytherins doing alone in the Forbidden Forest? Mr. Malfoy has more sense than this... What a fiasco."

Harry didn't answer. The sense of doom was as strong as Harry could ever remember feeling it, a feeling of power in the air so great that it was almost tangible. Some part of him was still viscerally shocked at how fast the shields surrounding the Aurors had been torn apart. He almost hadn't been able to see the successive lashes of color which had torn away the shields like tissue paper. It made the duel Professor Quirrell had fought against the Auror in Azkaban look like a mockery, a child's game - though Professor Quirrell had claimed, then, that if he'd fought for real the Auror would have been dead in seconds; and Harry knew now that this was also true.

Just how high did the power ladder go?

"I take it," Harry said, managing to keep his voice steady, "that your eating unicorns has something to do with why you'll get fired from the Defense Professor position. I don't suppose you'd care to explain in considerable detail?"

Professor Quirrell looked at him. The almost tangible sense of power in the air seemed to diminish, drawing back into the Defense Professor. "I shall indeed explain myself," the Defense Professor said. "I need to cast a few Memory Charms first, and then we may go off and discuss it, for it would not be wise for me to stay. You will return to this time later, as I know."

Harry willed himself to be able to see through the Cloak he had mastered; and knew that another Harry stood beside him, hidden by his own Deathly Hallow. Harry then told his Cloak to hide himself from himself once more, and it did; being able to perceive your future self meant having to match the memory later.

Harry's own voice said, then, sounding strange in present-Harry's ears, "He has a surprisingly good explanation."

Present-Harry remembered the words as best he could. Nothing more was said between them.

Professor Quirrell walked to Draco's form, and chanted the spell of the False Memory Charm. The Defense Professor stood there for perhaps a minute, seemingly lost to the world.

Harry had been studying Obliviations, these last couple of weeks - though he couldn't have helped cast the spells, unless he was willing to exhaust himself almost completely, and for some reason they wanted an Auror to lose every single life memory involving the color blue. But Harry had some idea, now, of the concentration which the far more difficult False Memory Charm entailed. You had to try to live the other person's entire life inside your own head, at least if you wanted to create the False Memories with less than a sixteen-to-one slowdown as you separately crafted sixteen major tracks of memory. It might have been quiet, there might have been no outward sign; but Harry knew something of the difficulties now, and he knew to be impressed.

Professor Quirrell finished, and moved on to Tracey Davis, then the three Aurors, and finally Professor McGonagall. Harry waited, but future-Harry made no protest. It was possible that even Professor McGonagall, if she'd been awake, wouldn't have protested. It was not yet the Ides of May, and apparently there would be a surprisingly good explanation.

With a gesture, Draco's stunned body was lifted, and sent a short distance into the woods, before being carefully deposited on the ground. Then a final gesture from Professor Quirrell ripped a huge chunk out of the unicorn's side, leaving behind ragged edges; the raw meat hovered in the air, then wavered in Vanishment and was gone.

"Done," Professor Quirrell said. "I must depart this place now, Mr. Potter. Come with me, and remain here."

Professor Quirrell strode away, and Harry followed and remained behind.

They walked through the woods in silence for a time, before Harry heard faint voices in the distance. The next set of Aurors, presumably, after the first set had fallen out of contact. What his future self was saying, Harry didn't know.

"They won't detect us, nor hear our speech," said Professor Quirrell. The sense of power and doom around the Defense Professor was still strong. The man seated himself on a tree stump, one where the light of the almost-full moon fell full on him. "I should first say that when you speak to the Aurors, in the future, you should tell them that you frightened away the seething dark, the same as you did that Dementor. It is what Mr. Malfoy will remember seeing." Professor Quirrell gave a small sigh. "It may cause some alarm, if they conclude that some horror kin to Dementors, and strong enough to break the Aurors' shields, is loose in the Forbidden Forest. But I could not think of what else to do. If the forest is better-guarded after this - but with any luck I have already consumed what I need. Would you mind telling me how you arrived so quickly? How did you know Mr. Malfoy was in trouble?"

After Captain Brodski had learned that Draco Malfoy was in the Forbidden Forest, seemingly in the company of Rubeus Hagrid, Brodski had begun inquiring to find out who had authorized this, and had still been unable to find out when Draco Malfoy had missed check-in. Despite Harry's protests, the Auror Captain, who was authorized to know about Time-Turners, had refused to allow deployment to before the time of the missed check-in; there were standard procedures involving Time. But Brodski had given Harry written orders allowing him to go back and deploy an Auror trio to arrive one second after the missed check-in time. There had been a Patronus Charm to locate Draco, which Harry had successfully willed to take the form of a ball of pure silver light, and the flight of Aurors had arrived on time to the second.

"I'm afraid I couldn't say," Harry replied evenly. Professor Quirrell was still a major suspect, and it was good for him not to know the details. "Now why are you eating unicorns?"

"Ah," Professor Quirrell said. "As to that…" The man hesitated. "I was drinking the blood of unicorns, not eating them. The missing flesh, the ragged marks upon the body - those were to obscure the case, to make it seem like some other predator. The use of unicorn's blood is too well-known."

"I don't know it," Harry said.

"I know you do not," the Defense Professor said sharply. "Or you would not be pestering me about it. The power of unicorn's blood is to preserve your life for a time, even if you are on the very verge of death."

There was a stretch of time when Harry's brain claimed to be refusing to process the words, which was of course a lie, because you couldn't know the meaning you weren't allowed to process, without having already processed it.

A strange sense of blankness overtook Harry, an absence of reaction, maybe this was what other people felt like when someone went off-script, and they couldn't say or think of anything to do.

Of course Professor Quirrell was dying, not just occasionally ill.

Professor Quirrell had known he was dying. He'd volunteered to take the Defense Professor position at Hogwarts, after all.

Of course he'd been getting worse the whole school year. Of course illnesses which kept getting worse had a predictable destination at their end.

Harry's brain had surely known already, somewhere in the safe back of his mind where he could refuse to process things he'd already processed.

Of course that was why Professor Quirrell wouldn't be able to teach Battle Magic next year. Professor McGonagall wouldn't even have to fire him. He would just be -

- dead.

"No," Harry said, his voice a little shaky. "There has to be a way -"

"I am not stupid nor particularly eager to die. I have already looked. I had to go this far simply to last out my lesson plans, having less time than I had thought, and -" The head of the dark moonlit figure turned away. "I think I do not want to hear about it, Mr. Potter."

Harry's breath hitched. Too many emotions were bubbling up in him at once. After denial came anger, according to a ritual someone had just made up. And yet it seemed surprisingly appropriate.

"And why -" Harry's breath hitched again. "Why isn't unicorn's blood standard in healer's kits, then? To keep someone alive, even if they're on the very verge of dying from their legs being eaten?"

"Because there are permanent side effects," Professor Quirrell said quietly.

"Side effects? Side effects? What kind of side effect is medically worse than DEATH?" Harry's voice rose on the last word until he was shouting.

"Not everyone thinks the same way we do, Mr. Potter. Though, to be fair, the blood must come from a live unicorn and the unicorn must die in the drinking. Would I be here otherwise?"

Harry turned, stared at the surrounding trees. "Have a herd of unicorns at St. Mungos. Floo the patients there, or use portkeys."

"Yes, that would work."

Harry's face tightened, the only outward sign behind his trembling hands of everything that was welling up inside him. He needed to scream, needed some outlet, needed something he couldn't name and finally Harry leveled his wand at a tree and shouted "Diffindo!"

There was a sharp tearing sound, and a cut appeared across the wood.

"Diffindo!"

Another cut. Harry had learned the Charm only ten days previously, after he'd started getting serious about self-defense. It was theoretically a second-year Charm, but the anger pouring through him seemed to know no bounds, he knew enough now not to exhaust himself and he still had power yet.

"Diffindo!" Harry had aimed at a branch this time, and it plummeted to the ground with a sound of twigs and leaves.

There didn't seem to be any tears inside him, only pressure with no outlet.

"I shall leave you to it," Professor Quirrell said quietly. The Defense Professor rose from his tree stump, the unicorn's blood still moonlit on the black cloak he wore, and drew his hood back over his head.