"Wither, Cat."

The candles were no longer suspended but falling towards the flagstones, and their light too bright and the hush too still. He willed his feet forwards, willed them not to stumble, and sat clumsily on the stool.

The sea of bright faces swam in front of him, all the eyes glassy and luminous, before the hat fell down over his forehead to rest on the bridge of his nose.

"Hmmm," it whispered into his mind, and all he could smell was pungent old leather. "Another curious case of a Muggle-born wizard. I pity the likes of you, I really do."

His mind was roaring hot. He took a shaky breath, choking on the leather must, and willed it quiet.

"You're brilliant, very powerful. That much is clear. But all those murky depths…," the hat hissed. "Best you unlearn some discpline. Better be…"

"RAVENCLAW!" bellowed the hat to the hall. Cat suppressed his flinch.

The stern lady in stiff green robes pulled the hat off his head and pointed him to one of the long tables. Kids of all ages were grinning at him, clapping, waving him over, but he couldn't see any space on the benches. He felt tears pricking at his eyelids.

"Cat," someone tugged on his sleeve.

He recognised her from the train, or maybe from the expectant throng outside the Great Hall, though he'd been too sick with nerves to meet anyone's eyes.

She scooted up the bench, "Sit here."

"Thanks," he whispered.

Disembodied hands clapped him on the shoulder as he sat down, and voices shouted congratulations. He mustered a wan smile in no direction in particular. The hat keep shouting episodically, interspersed with roars and cheers.

"A speech, then food is what they tell me," his neighbour muttered into his ear. "Think we could all use something to eat. Don't know about you, but at this point I would eat a troll. Raw."

He managed a chuckle that got stuck in his throat.

"I'm Amy."

He met Amy's eyes, which were definitely not a normal colour. "Cat. Thanks for rescuing me."

"Not a problem," she knocked his elbow.

A tall woman of indeterminable age with long black hair, so sleek it was almost reflective, stood at the podium. Cat found himself, absurdly, thinking of pictures of Cher from her Cher & Sonny Show days. The woman clapped her hands above her head, causing the sleeves of her robes to fall down her arms and reveal twisting creatures tattooed down her forearms. The sound of her clap thundered off the walls.

"Speeches are wasted on the hungry," she called. "Instead, let us feast!"

The applause was cacophonous and the tables creaked, bowing under the sudden weight of silver platters, steaming tureens and spindly ornamented racks of plates.

"Fuck me," Cat whispered. Amy snorted.

Some pleasant time passed with jugs of gravy and the cracking of pie crusts. A beautiful boy with yellow eyes spiked Cat's drink with something blood-red, muttering that he looked peaky. Amy stole a sip and grinned appreciatively. He warmed, slowly, as he devoured flaking pastries filled with strangely spiced minced meat.

"Pudding." "Pudding." "Sugar!" Hoarse whispers proceeded a rippling shimmer that spread down the long tables, as silver plates and towers of crumbs disappeared, replaced by gold and swirls of frosting. Everyone armed themselves with forks and dove towards the cake stands.

Amy laughed, a peal. "I didn't pace myself. Fuck's sake."

Cat grinned. "Neither."

The yellow-eyed boy pushed a platter towards them. "First banquet speciality."

They were crumbly yellow tarts, remarkable only for their unassuming presentation in the middle of all the ornate sugar work and general splendour. Amy took a deep breath and a bite. Her eyes flickered closed.

"Cat, you have to. Thanks, man," but the yellow-eyed boy had already turned back to his friends.

It melted in his mouth, sharp and sweet with something burnt lingering underneath the citrus. Cat swallowed, overcome by the surreal. The blazing candle-light, the dark shadows and robes, the cacophony of laughter and unknown tongues and accents, the tug of magic pulling at his gut, seeping from every stone of the building – it frightened him. It felt feverish, impossible, the kind of incandescent that spelled inevitable loss.

"The best thing I've ever tasted," he told Amy. The yellow-eyed boy caught his eye and nodded.

And then the plates disappeared, and the Cher-looking lady stood again.

"Speeches are also wasted on the well-glutted, I fear. Instead, my stuffed students, permit me some brief remarks. As most of you should well know by now, the Forest remains Forbidden. As is any sneaking, carousing or adventuring after dark. The castle continues to house magicks and artefacts potentially both enlightening and dangerous to your impressionable minds – I advise caution. Keep your wits about you. We will have need of them!

"Now, first-years, your perfects will guide you to your rooms. Thank you for sharing this fine meal with us all."

A smiling girl stood at Cat and Amy's table. "Get over here, Ravenclaw first-years."

Cat and Amy drained their cups and gracelessly clambered over the benches, joining the huddle of sated children.

"I'm Grace, your prefect," the girl said. Cat's his eyes raked across her cheek and neck, where a deep purple vine of a birthmark writhed. Her hair was wrapped in blue and bronze and her eyes were close to indigo. He could feel the power flowing off her. It felt like a breeze, and tasted green. She caught his eyes and he could swear she winked. "Follow me. We're stopping by the infirmary before you get to see our tower – Madame Sorrell wants to make sure none of you will be succumbing to poxes or lurgies."

She turned and swept out the hall, trailing sated and stumbling first-years.

After the fifth or maybe tenth turn, Cat gave up on trying to remember their route. The hallways reeked with magic – he felt assailed by each tapestry, each suit of armour, even the occasional torch bracket. Sconce, he thought. The stones were babbling. He sensed the castle was celebrating too, following the first-years' footsteps, excited to take their measure.

The infirmary was hearth-warm, with enormous windows gaping out into the night. Madame Sorrel was a young women with the long fingers of a pianist and a broad smile. She called them into her office, one by one. Cat waited, gazing out the window, as the nurse called for Athinum and Greenlop and Percival and Winsome and –

"Wither."

Cat realised he was shaking as he stepped through the door.

Madame Sorrell looked up from her notes, and tsked, her forehead knitting in concern. Cat noticed she had no eyebrows, and wondered how he'd missed that before.

"Sit." Cat sat. "Do you mind if I touch your head?" she asked gently.

Cat shook his head, not trusting himself to speak. She ran her fingers across his crown, his brow, his temples, behind his ears.

"Muggle-born, I take it?" Cat nodded.

"It's a wonder, really it is." She patted his shoulders and moved back behind her desk, steepling her fingers against its top.

"Forgive me asking, but how do your parents name you?"

"C-c-Catherine?" Cat choked on it.

She hummed sympathetically. "I'll need to see you Sunday morning. If anyone asks, it's for dragon pox immunisations. Fairly common requirement for Muggle-born first years.

"But, in truth, Wither, it's because we have a lot to do together. My brief examination has made clear that you've spent the last five years, minimum, devoting and developing a significant amount of your rather extraordinary magical abilities towards suppressing puberty. It's why you're so small for your age, and why you probably feel tired all the time. You've been holding up a heavy, heavy weight all by yourself for a long time.

"I can teach you to how to use magic, talismans, plants or potions to do some of the heavy lifting for you, so that you can free your powers up. Your body and talents are yours to nourish as you see fit. You're a powerful, resilient young magician I want to see grow and flourish. How does that sound?"

Cat gazed at her, dumbfounded. She smiled, slow and warm.

"There's so much in store for you, my dear. I'm glad to have met you." She knelt and rummaged in her desk.

"Take this," she tossed a small piece of flint to him. It radiated warmth in Cat's hands. "It's rather generic, but should lift the load some and let you properly metabolise that lovely dinner. Keep it with you – in your pocket or under your pillow."

She stood and clasped his shoulders, closing her eyes and whispering something. Cat gasped as the flint flared hot. Madame Sorrell lifted her hands from his shoulders and something came with. He felt like floating. His chest was light, his collar-bones loose.

She grinned, "Remarkable. Glad to have freed you up some. Come see me tomorrow after dinner. Off you go."

Grace gave him a sharp look as he walked out the office. Amy gave him a quick, one-armed hug. He wondered what his face was doing.

"That's us done here – to the tower, my wee first-years." Grace fell in step with him as they walked through more interminable corridors and up staircase after staircase. "You burn very hot, Wither. Glad we have you with us."

"Thanks?"

"I don't know what Sweet Sorrell did, but I'm glad she did it. I can sense you much more clearly now – very blue. I look forward to seeing more of you."

Cat didn't know what to say to that.

Grace stopped in front of non-descript door with a small bronze door-knocker shaped like a bird of prey. "We're at the top of South Wing of the castle – nineteenth floor from lake elevation, seventh from the grounds. This door is the way into our tower. To gain entrance, you must satisfactorily answer its question. Simple enough, in theory."

The gold bird rustled its feathers, clinking quietly, and tilted its head. "From you, Prefect, I only want to know: are they good eggs?"

She ran a finger over its head, "As you are well aware, it's all in the hatching."

The door swung open to reveal more stairs. A collective groan. Grace laughed and said, "Think of your calves, your glutes, little wizards!" They followed her round and round, up and up, past windows slitted, stained-glass, wide-open, black and jewelled with the night sky, until they came up in the middle of wide round room thick with carpets and chatter and the sweet smoke of burning hearths at each compass point. Everywhere were coffee tables and stack of books and shelves and maps and windows and lounging students. The yellow-eyed boy was sunk in an armchair, face buried in a book. To the right of one of the fireplaces was the start of another spiral staircase.

"Up there," Grace pointed to the staircase, "are your rooms. They're in no particular order – you find yours when you come to your nameplate. Your belongings are already there, for which we give thanks to our fine house-elves and their great and mysterious magic. Bathrooms are shared between every two or so rooms.

"Welcome to your home. There are kettles on the fire if you want tea or cocoa before bed, packs of cards on the tables, books aplenty. I'll be up for the next hour or so if you have any questions and I'll see you tomorrow bright and early to lead you to breakfast." She walked off to the East fire, snagging a mug off a rack on the wall.

Amy turned to Cat, "C'mon, let's find our beds. I'm ready to pass out." They followed the straggling pack of other first-years up the stairs, everyone peering at the nameplates in the torch-light. The group slowly thinned as people found their names. Almost a hundred stairs up, Amy found herself – Amarelia Thyme – and turned to give Cat a hug. "I'm so glad to have met you. See you tomorrow. Hope you don't have much further to go."

"Same, Amy. See you. It'll be fine – I'll, uh, just think of my ass muscles." She grinned at him, and stepped into her room. Cat caught a glimpse of bare stone flickering with orange firelight and a blue-sheeted and -canopied bed before the door rasped closed behind her.

Cat kept going, up and up past unfamiliar names on unfamiliar doors as his legs burned, until he saw a hatch door set in the ceiling in front of him and knew he'd reached the top of the tower. He sighed, starting to worry it had all been a mistake. Then he noticed the nameplate set on the hatch – Cat Wither. He pushed up the hatch and steps rattled down. He clambered into a perfectly round room with a four-poster bed pushed against a wall, his luggage arranged at its foot. There was a skylight set into the ceiling, four windows spaced equidistant, and a black stove in the centre of the floor, its pipe extending out the roof.

Cat shucked off his shoes and threw himself on the bed, gazing up into the sky. His heart was hammering and he let it beat itself slower and slower, until his ears began to prick at the whoosh of wind around the tower top and ping of first rain drops on the glass above his head. He slowly became aware of a feeling against his thigh – a warmth, or a prickling? The traces and tastes of magic are hard to describe – and remembered the flint he'd cradled in his hands and slipped into his pocket in Madame Sorrell's office.

He pulled it out, marvelling at its potency, all the flecks of charm and resonancy dappling its surface and threading through its mass. He pulled his awareness through it, like a magnet along an iron bar, trying to trace its substance. It felt curiously awake – Cat reminded himself never to underestimate rocks.

He could feel its connection to him, but couldn't quite follow what it was doing or how. It felt trustworthy, though, so he slid it under his pillow and lost himself to sleep.