Confusion and concern on their faces. They stand here at the heart of Britain's greatest school of magic, yet all that is known is how little they know. They are Hogwarts's leaders, yet in the still and stagnant air hangs indecision. Whatever haunts the school, it has eluded Neville and the other heads of house as much as anyone who walks these halls.

Minerva McGonagall speaks first. "The merpeople know nothing of it," she says, her voice grave, her face graver. Half-closed eyes sunken behind shadow. Graying hair looking more frayed than ever. Age's steady advance accelerating with each passing day, each mounting worry. "Their chieftain knew him as one of their guards, but they hadn't even known he'd gone missing, let alone died. They sounded shocked."

"So they're as clueless as we are," Neville murmurs.

Silence again settles in the Headmistress's chamber. An old, bronze-inlaid clock ticks away in the corner, each second passing with unbearable noise in the tight and tense confines. The portraits of headmasters and headmistresses past surround the stone-walled room, most asleep, the others dozing or idle or off to visit other paintings around the school. Neville looks up at the portrait directly above McGonagall. An old, wizened, white-haired man. Half-moon glasses. Sound asleep.

What would Dumbledore be saying now?

The balding man to Neville's left clears his throat. "Not that I want to drag down the mood any further, if that's even possible, but I've noticed some strange behaviors with the ghosts lately. One or two here and there moving erratically, often late at night when I'm walking the halls."

"Erratically?" McGonagall says.

"As if they freeze in one place then appear several seconds later in another. Like stop-motion photography. Odd contortions, strange, almost bestial noises. Every time I've asked them about it, they remember nothing."

"Which ghosts, in particular?" asks the messy-haired, thickly-built man to McGonagall's right. Justin Finch-Fletchley. The only of Neville's schoolboy classmates to hold a post here, and the head of Hufflepuff as Transfiguration professor.

The balding man grits his teeth. Dalibor Kos, Ravenclaw's head of house, master potioneer, and the professor that Neville still knows least about despite years of working with him. Much of his past is shrouded in mystery, given that he left Britain following his 1991 graduation from Hogwarts and, according to him, traveled about other parts of Europe throughout the war against Voldemort. He's a muscular man, the fitness of youth still about him despite his disappearing hair and weathered face. There's something else too, Neville thinks. He doesn't move like a bookish man. There's no stiltedness, no awkward motion as accorded to one used to years of scholarly pursuit, but an activity, a restlessness inherent to him as if some hungrier, stronger spirit inside yearns to get out. "Both the Friar and Nick. Peeves isn't a ghost, exactly, but even he was acting oddly once. He was almost, well, nice—if you can believe it—when I asked him about it."

"Definitely not Peeves, then," Justin snorts.

"How can we be sure these are actually connected?" McGonagall interrupts. "I'm not doubting any of your testimonies, but it is just as much a folly to jump to conclusions and take the wrong action as it is to fail to act."

Selena Avery shakes her head. "There's a common connection. Ghosts acting erratically, paintings behaving as they shouldn't. Now merpeople. It's like something is working its way up through possession, taking hold of more and more advanced minds as time goes on. Like it's learning and scouting out Hogwarts."

"How do the merpeople fit into that?" Justin asks.

"They live in the Black Lake, don't they? All the sewage pipes flow into it."

"If it's already in the ghosts, then it's already in Hogwarts. Why care about sewage pipes?"

"It warrants us being proactive, rather than sitting by and waiting," Selena says, her voice growing more agitated in response to Justin's questioning. "If I'm right—"

"If."

"Yes, if, and follow along for a minute. If I'm right, then what's to stop this, well, thing, from taking the next logical step and possessing a person? Maybe a first-year student?"

"Because it's still a theory," Neville says. "If we take the wrong move and—"

"If we do nothing at all—"

A soft voice chimes in, and all in the room fall silent. "Sometimes nothing at all is exactly the right step to make, Professor Avery."

In his portrait, Dumbledore's painted likeness stirs. There's a tiredness to him, as if he's kept aging all these years since his death, but that same sparkle in his eyes that Neville remembered seeing even on his very first day at Hogwarts still shines as bright as ever. Always, he thinks. "If there is one recommendation I can always remember hearing from a certain Alastor Moody, it's the need for constant vigilance," Dumbledore's painting says. A subtle smile. A quick flick of his eyes towards McGonagall. Then he looks back towards the young head of Slytherin house as gravity retakes his expression. "One needn't act to make the best move in every situation."

"Might you explain further, Albus?" McGonagall says.

"I've always found that anyone of real conviction, anything with a goal, will show their hand eventually. Even I did, near the end," he says, holding up his right hand and smiling softly. "Neither student nor staff has been hurt so far, correct? That is your first and foremost responsibility. As teachers. As leaders. As those to whom everyone at Hogwarts looks up to. If there is some dark presence haunting these halls, if it does have some malevolent goal in mind, then it will not stay content forever. It will show its hand. And—" again he holds up his hand as Selena opens her mouth— "If I might finish, Professor, you must be ready for that moment. If you wish to be proactive, then prepare. Lashing out now when you know so little is reactive. But stand together, prepare, and believe in each other's strength beside you, and you will do what is right when the time comes. Because our greatest strength doesn't lie in schemes and strategies. It lies in our unity, and our faith in our friends."

Silence seizes the room again as Dumbledore's likeness falls back asleep. Silver-white moonlight shudders on the old, cold stone. Everything still in the night. As if they five teachers arranged here are but a painting as well: A still life between the relaxed peace of before and whatever might come ahead, be it nothing or everything. The air itself is stone in Neville's lungs.

Professor Kos finally splits the stillness. "If I may play the pessimist, how long can we keep our suspicions just among ourselves?" he says, his voice deepening, darkness shading his eyes. "Our students are not fools, nor are they blind. If we see things out of the ordinary, then eventually they will, too, if they haven't already. What do we say when that time comes?"

"Leave that to me," McGonagall says, turning her back to them and looking up towards Dumbledore's painting. "It is my job as Headmistress to keep the peace here. To make sure that every student can learn and grow safely. When that time does come, I will handle it. I only ask that each of you ease the worries and concerns of each of your houses. If we do have an unseen enemy in our midst, then panic and fear will undo us before our foe ever can. That is all for tonight."

The others file out until only Neville is left with the Headmistress, silence again settling between them. This time it does not last long. "It has been nice, Neville," McGonagall says quietly.

"What has?"

"These peaceful years. All that time since you were a student and I was but a teacher. But I suppose nothing lasts forever."

Fennel and formulae; beetle larvae and bitterroot. Mind your proportions. Stir twice, clockwise then counterclockwise, wait until the first bubbles. Then again.

There is little fancy wandwork in potions. Few incantations, little guessing, few fancy touches that might send a spell awry like in Charms. Potions is a magic of the mind, brainpower made manifest, its path spilling forth like an open road with danger lurking on both sides—yet if the traveler is clear of head and dedicated of purpose, there is nothing stopping them from walking that road and meeting their destination. Yet so many falter. So many veer off the road, miss a turn, spill into the wrong alley. Read the wrong formula. Add too few larvae; slice their fennel too finely by the slimmest of margins. But not Rose. This is her strength, her confidence. Where her heart might find its fortitude again, where learning comes as naturally as walking. Potions is clarity and precision, science crossing blades with magic, so far removed from the messiness and vagueness of Charms, and in such clear state of mind she knows just what to do.

"You see? And you said you were only okay at potions. Professor Kos was right about you," Madam Maclear cheers, looking over Rose's shoulder as her miniature cauldron gurgles with a thick mint green slurry. "It looks perfect! At least you better hope it is, since you're going to be drinking it."

Rose wrings her hands. "It's probably poisonous."

"Oh no, you're not going to get out of it that easily," Madam Maclear says, walking away while wagging a finger behind her with a leisurely air. Again they are the only two in the Hospital Ward, afforded a privacy that allows the walls between staff and student to lower, if only just. "You're getting a good night's sleep this week whether you like it or not. Now that let that sit for a few minutes. It needs to cool and congeal before the finishing touches."

Pale sunlight of a waning afternoon. The hoo-hoo cadence of a barn owl swooping towards the Owlery with a letter in tow. Laughter of two Hufflepuff girls on the grass below. The aroma of fennel clinging to Rose's hands. It all seems so peaceful. So relaxed. A stillness in this moment where no one else need see her. She watches through the arching window as the Slytherin Quidditch team practices in the distance, looping whirls and swiveling spins, Quaffle and Bludger and Snitch aflight, seven fliers aflit like swallows, dive, rise, dive. Life and motion.

"It must hurt," Madam Maclear says softly, following Rose's eyes. "Bad luck's terrible like that."

Rose looks away. "Hm?"

The matron nods towards the Quidditch practice. "What I hear is that you're a good flier," she says, "and that's something that a tryout can't take away from you. Most things in life are beyond our control. We can only worry about what is in our hands. Making a team isn't something you can decide on your own. Your skill is yours, though. Don't fault yourself for misfortune."

"I'm not going to get another chance at it," Rose mumbles, wrapping her arms around herself.

"Why not?"

"Because the tryouts are based on seniority for Ravenclaw. I need some other Chaser to leave to get on the team, and I don't know if that's going to happen," she blubbers. Tears welling in her eyes. Don't let the matron see.

Madam Maclear shifts in her seat. "Are you going to let that stop you from trying?" she says. Her voice clear, steady. Strength settling in each word. Like the rumbling of a distant storm. "It wouldn't stop me."

Rose closes her eyes. She should agree. It shouldn't stop her from trying, either. Mum and Dad would tell her the same. Uncle Harry and Aunt Ginny, the same. But they are made from stronger stuff. They are heroes from a generation of survivors. She is just Rose. "I dunno."

"Well, you have plenty of time to think on it. Let's leave such dreary stuff behind," says the matron, rising. "I wager your potion's ready. Let me grab it."

Returning with the miniature cauldron in hand, she pours its contents into a vial while changing the subject. "I heard from a boy this past week about some nightmare assignment in History of Magic for fourth-years. Something about a year-long essay about the school founders? Drink up."

Rose swigs down the potion. Dreamless sleep for the week. It has worked so far—the nightmares averted, the exhaustion waning little by little, normalcy creeping back into her life even as a certain sadness remains. The year isn't going as she wants. No Quidditch. Her friendship with Scarlett feels more distant than ever. Al seems too busy to talk most of the time. It all culminates in a thickening loneliness, as if amid hallways teeming with students and magic she is a wanderer apart, sifting through some ruin of her heart's design. Alone within the crowds. "Yeah. We got that our first week."

"Oh? And who'd you get?"

"Salazar Slytherin."

All at once something shifts in Madam Maclear's demeanor. A shadow flits across her face. Darkness washes over her eyes. And as soon as it comes it is gone, her cheery personality returning, as if a phantom slipped within her for but a moment only to flee to safer havens. "I see," she says, taking the empty vial from Rose's hands. "Not exactly a good man, as far as legends go."

"He founded Hogwarts."

"Helped found it. And evil men can do good things. History's full of Salazar Slytherins," the matron says, setting the vial aside.

"I don't know that much about him. Just what Professor Binns says in class."

"So you haven't started your essay. I know how that goes," the matron says with a smile. "Well, I can't say I can write an essay for you, but if you have any homework woes, or need to get anything else off your chest, I'm always here and happy to listen. And help, however I can.

Rose believes her. More than she believes in herself.

No secret stays hidden for long, and no good thing can continue without running into an obstacle. So it is in Charms that Rose hears the first whispers.

It is a pair of Gryffindor girls in the corner of the class near the door, chairs huddled up together while Professor Lancaster idly flips through sheets of parchment at her desk, not even bothering to look up at her class. Rose watches from the corner of her eyes as the girls whisper, mouths guarded by hands held dramatically before their lips as if they are exchanging state secrets, their eyes alight in the moment. Gazes flicking over at Rose, then away. Then back again.

After class one of the girls corners Rose as she shuffles down the hall past a portico. Tall, brown-haired, pretty. Gryffindor's alpha girl among the fourth-years, Muggle-born Gemma Brax. Even in a house with the likes of the Potters, Gemma stands out. Rumor, as Rose has heard it, is that even Isaac Zabini has looked her way now and then. "What'd you do?" Gemma accosts her, bodying her into the portico with the way she sticks her hip out and plants her hand on it. Confident. Self-assured. Aggressive. Like a lion cornering prey.

"I didn't do anything," Rose says, holding her Charms textbook across her chest like a shield.

"Didn't do anything," Gemma repeats in a nasally tone. "That why you're getting private tutoring from the new matron? What'd you do, have your parents buy her off because she's new at school?"

Of course. Of course word gets around that Rose has been making the weekly trek to the hospital ward, even weeks after she's recovered from her Quidditch injury. Of course word turns into rumor turns into gossip, a wind becoming a gale becoming a storm until destruction is unleashed. "I'm not getting private tutoring."

"Oh yeah? Whatcha keep going to the hospital ward for, then? You don't look sick to me."

Rose looks at her feet and stays quiet. It's like Madam Maclear said. It's outside of your control. Don't worry about it.

That does not dissuade Gemma, however. "Can't come up with anything? Thought so," the Gryffindor girl says. She wraps a loop of hair around her index finger, playing the innocent, eying Rose as if toying with a mouse. "I guess it makes sense. You never struck me as very smart. Needed to get help on your assignments?"

"What?"

"Oh, come on. Just fess up. Don't act like you're above all that. You're not like your cousins. You're not a Potter. Just another Weasley. There's, like, a million of you. You don't have to be stuck up about it."

"That has nothing to do with it," protests Rose. Heat flushes her face. As if Gemma cares an iota about magical families and blood purity.

But any vulnerability is an advantage to be utilized. And as much as Rose tries to deflect, tries to defuse, it only lures Gemma onward. "O-kayyy," she says, rolling her eyes. "Some of us little people could use some help on our homework too. Sure would be nice of a teacher would give me pointers, even if it's just the matron. That's really why you keep going to her, huh? Using what happened to you in Quidditch to get in good with the staff? Maybe cry a little while you're there to sell it? Psh. Rich girl problems."

"It's not—leave me alone."

Gemma sticks out her lower lip. "Sorr-ry," she slurs. As one of her friends calls to her, she does a half-turn, looks back at Rose, and adds, "It's called nepotism, Rosie. You're in Ravenclaw. I'm sure you know what a big word like that means."

Then she prances off, hurrying to catch up with a whole gaggle of other girls, leaving Rose alone with only her book to cling to.

If only it stopped there. Late that Friday night the gossip trails from a corner of the Ravenclaw common room, where Honoria and Imogen huddle together beneath one of the arched floor-to-ceiling glass windows and whisper while throwing incriminating looks Rose's way. Minutes tick by and they only grow louder, as if intentionally trying to aggravate her. Rose tries to bury her face in her Charms homework—the Freezing Spell's many uses include preservation of perishable food (Was that it? What page was that on?) as well as—but Rose's mind fractures and drifts as the whispers slip by her defenses. She tosses her textbook on the table in front of her, leaning back amid the cushions of her couch and staring up at the ceiling. A magical array of constellations and night sky circles on the ceiling above while a massive bronze astrolabe dangles in the air. The freedom of the stars to revolve in the heavens. To set upon their paths every night without delay, without hindrance, without anything or anyone to drag them astray. Rose closes her eyes. Darkness beyond that starlight, infinite, timeless.

"Just ignore them."

Rose opens one eye and looks at Scarlett next to her, pressing quill to parchment. A placid flatness on her face. Eyes like half-moons. "They'll get bored eventually."

"I doubt it," Rose grumbles, but she leans forward, back over her homework, and presses on.

Before long it is just the two of them in the common room, the rest of Ravenclaw house retreating into their dormitories for the night, the constellations yet revolving on. Without end, without fail. Rose sets down her quill and rubs her eyes, looking around to make sure that they're alone before saying, "How'd you deal with it?"

Scarlett is quiet for a moment before responding. Her eyes stay locked on her parchment. "Deal with what?"

Rose lets out a long breath. She hates deep conversations like this. Awkward questions at midnight. So much potential to trip up, like a runner navigating a minefield. Danger in every step. "In our first year, Honoria and Imogen and the others talked bad about you all the time. They said you were weird and a loner and worse stuff."

Scarlett lets her words settle before replying. "Hm."

"It didn't bother you?"

"I just ignored it."

"But how? You didn't feel anything from that? They were obvious about it."

"I didn't say I didn't feel anything. I just ignored it."

"But—ugh," Rose sighs.

Scarlett looks up at last. "I couldn't do anything about it. So I just ignored them. That's it. That's what you should do, too. Just keep going."

Worry about what is in your hands. Rose slumps over and presses her palms to her cheeks. "I guess."

Silence settles again. How common it is. Almost a comforting friend, the quiet, the warm, safe stillness. Nothing to intrude. No invaders, no attackers. Just quiet. Peace. She looks over at Scarlett's parchment. It's not homework but a sketch, a bird—a sparrow maybe, a swallow—aflight amid falling leaves. Black on white. Ink on parchment. Freedom and motion. Like stars in the sky. "Not doing homework?" Rose asks.

Scarlett shrugs. "Dunno."

"That's really good. Like, professional good."

Again she shrugs. "It's just a stupid thing," she says, before setting the drawing down. "It doesn't matter."

"Well…if you say so," Rose says. She tosses over her Charms homework. "Here. You can copy mine."

"Oo-oo, that's cheating," Scarlett says, taking the parchment. "Honoria might say bad things about us if she found out. Also, you spelled the Freezing Charm's incantation wrong in your first sentence."

"Well, duh. I'm rubbish at Charms."

The hint of a smile touches Scarlett's lips. "Okay. I'll just fix yours too, then."

"Oh, great. I guess I was helpful."

"You can do your Potions work and give me that, too, if you want. That's your subject, not mine."

"I already did it."

Scarlett stifles a giggle. A hushed and tinkling cheer. "This is fun. We're up on a Friday night doing homework."

Rose doesn't bother hiding her chuckle. "Yeah. We're in Ravenclaw. This is supposed to be thrilling," she says. She folds her hands, looks about, and then says, "I feel stupid just watching you fix my homework." She takes Scarlett's drawing. "Can I color this, at least?"

Her friend looks at her as if she's insane. "Uh, sure. You can have it if you want it. It's just a doodle."

But it is much more than just a doodle to Rose. It is strength, it is unity. For there is no greater strength than the faith born by friendship, the little moments like this, just two girls side-by-side with only the stars themselves as witnesses, revolving about and about in their ceaseless, timeless arcs.

Again Augustus Rookwood is running. This time it is not Aurors chasing him.

Over log and past tree. Foot catching on a loose root. Stumble, catch yourself. Push on. Don't let the stitch in your side slow you down. He looks skyward, wand aloft, the omnipresent green of the forest all around him closing in like some verdant hell intent on trapping him here forever. He cannot Apparate. He cannot summon a broom. He cannot escape.

Then—there it is. The cawing. The sound of crows.

They billow up overhead, darting and pinwheeling like a great circus in the air, black on sky blue. Dozens. Hundreds. Spiraling and veering in great motions like an aerial tide, ceaseless, unstoppable. Rookwood hurries. Run. Run.

The crows see him.

He cannot escape.

Run.

But he does not make it far. When he reaches a clearing he stops, realizing his mistake. Out in the open is death. They—it—his pursuer, whatever it may be—will run him down out there. But hesitation is defeat, and as he pivots to turn the crows align as if guided by divine force and rush at the ground like a thunderbolt hurled from on high. They slam into the earth mere meters before him in a great cloud of smoke and earth—and then he sees it rise again.

It forms from the ground up. Earth and stone and wood rushing up like a geyser to form feet, then legs, spindly, bony things. Tall and imposing like some giant out of barbaric myth. The geyser rises, the smoke thickens, and the elements, the woodlands, rush together in a great surge to form a torso, a chest. Long, gangly, bony arms ending in talons. Up and up. A skeletal deer's head. Massive antlers wider than Rookwood's arms stretched from fingertip to fingertip.

The crows are gone. In their place stands a monster.

Its horrible head tilts. Eyeless sockets look upon him.

But Rookwood is a Death Eater still, and he is not defenseless. Out comes his wand waving like a saber. "Avada Kedavra!"

The beast raises its arms in defense, but the Killing Curse still strikes its right forearm. Green light. A rushing roar. Wood and bone splinter as if an explosion has detonated some primeval armory. When the smoke clears the beast is missing its right arm up almost to the shoulder, and yet still it lives, staring at Rookwood as if he has done no more than tickle it.

Rookwood scampers backwards.

The beast squats down, stretching out its stump of a right arm. Again smoke rises. Earth and bone and wood rise. From the stump forms an upper arm, and elbow, bit by bit the shattered right arm re-forming as the elements come together. In mere moments the beast rises once more, whole again, both arms intact and dangerous enough to tear its Death Eater foe apart.

Rookwood turns, fires another Killing Curse over his shoulder, and sprints back into the trees. He does not bother to see whether or not he hit anything.

Past tree, over stump. Feet splashing through a stream without care, without consequence. Nothing more on the mind but run, run. Survive. Run.

A rushing line of roots erupt through the earth to Rookwood's left, racing like a fault line past him. Again smoke erupts from the ground and this time the beast materializes in mere moments, popping up before Rookwood before he has time to slow down. It raises its rebuilt right arm. Swings. He has just enough time to cast a hasty Shield Charm before it strikes him in the chest with full force.

The charm only blunts the blow, and the force of the impact sends Rookwood sprawling. He tries to get to his feet, his breath fled from his lungs, but the beast is upon him. It drops one arm like a hammer and with one blow shatters his legs.

Rookwood screams. His wand flies from his hand. Panic floods his thoughts as his fingers grasp for his weapon of their own accord. No, no. He cannot die like this.

A few more centimeters. His wand is right there in the soft earth.

Then a whoosh sounds, and suddenly his wand flies away. Into the air. Into a hand.

Rookwood looks up. Before him, beside the beast, stands a half-naked man with blue runic tattoos covering his upper body like a second skin. Blonde beard knotted and reaching down to his chest. Hair a barbaric, savage mess of knots and tails. "I had a feeling he wouldn't take too long to get you. He is pretty good," the tattooed man says, tossing the wand into the earth by the Death Eater's feet. Rookwood reaches out for the weapon and the man snaps his right fingers. Pain splits through Rookwood's head, and the Death Eater clenches his teeth, wincing. When he opens his eyes he spots the long, slender black line running beneath the skin of the tattooed man's right forearm.

Unmistakable. It is a wand.

"Ah," the tattooed man chides, "I heard so much about the Death Eaters. The name, obviously. But you look pretty mortal to me down in the dirt like that. Seems like you're doing a bad job living up to your reputation. How disappointing."

Rookwood is dimly aware of another presence. A cloak. A black shadow lurching from behind the beast. The monster bows its hand and steps aside, and even the tattooed man's taunts fall silent as the new arrival steps forth to confront his downed foe. At last Rookwood's voice stirs in his lungs. He coughs, chokes on pain and smoke and earth, and says, "Who're you?"

The cloaked man is silent at first. Nothing of him is visible: His face is a black pit beneath his hood, his body completely veiled by his attire. Then he speaks, his voice oddly clear. Almost peaceful. "An eye for an eye. A life for a life," he says. "But I can't kill you twice. So I'm going to have to make this count."

"Wait," Rookwood pleads as the cloaked man unsheathes a wand from the folds of his robe. Panic floods the Death Eater's mind. A new feeling, one he has never felt before, even in Lord Voldemort's presence during those old days. Not even when he was locked away in Azkaban, always sure there was escape or salvation waiting for him. Helplessness. "Wait!"

"Crucio!"