"Congratulations on your excellent Sleeping Draught essay, Mr Williams," an impressed Professor Ellis declared as he peered into Ville's cauldron, surveying its lilac depths. It was the Ravenclaw's Wednesday afternoon lesson with the Slytherins and Orville had been attempting to persuade Rose to join in on their almost-laughable plan. He'd flashed Albus and Rose a grin over their spacious work counters, his cousin calling it 'idiotic'. "Ten points to Ravenclaw," Ellis continued, stepping across the uneven flagstones, worn through years of students shifting around nervously. He rolled his sleeves up, revealing his sturdy arms, the paling fingers of a tattoo tiptoeing beyond his robe sleeves. "Although its consistency does make me wonder… Did you put your four Valerian sprigs in? It's not quite at its final stirring point…"

Whilst the flustered Liverpudlian scrambled to dice his missing ingredient, its brittle inner roots speckling his robes, Rose leant over and whispered into Albus' ear. "Are we really doing this? Breaking and entering and using a Professor's private possession without permission?"

"My gut feeling doesn't feel it's like something that's big enough to go and speak to McGonagall about," he repeated, measuring his third quantity of Standard Ingredient, a concoction of dried herbs his Magical Drafts and Potions manual had alleged was vital for first-year work. He obscurely remembered it being the least interesting item on his supplies list in the summer. "I want to make sure I'm not making a fuss over something silly, y'know." What else could they do apart from research more intensely?

The red-haired witch next to him exhaled pointedly, propping her hands on her hips and wrinkling her nose. "And doing this on a hunch is better because…? None of you have a plan. Not you, Ville or Sky. Are you just hoping for the best?"

Leaning down to check the cauldron was on medium heat to ensure he stirred the Standard Ingredient correctly, he looked up at Rose. "Mostly, yes. A regular weekday'll be best since she won't be stuck in meetings there and the portraits'll be asleep… If we go missing lessons, she'll know it was us. Plus, a distraction so we're lost in the chaos…"

Sky slid a thin green notebook across the scratched wooden surface towards Rose, who made a face as she thumbed through it, examining a number of frayed pages closely. There was an attentive stillness for a fraction of a second before she snapped it shut. "This is a list of all the odd Charms I learnt from working in the shop - there's a Latin translation spell that'll be perfect for whatever the daemon said. Grandad stocked millions of bloody Latin textbooks, like, who reads in Latin anymore?"

"Daemons do, apparently," Rose answered, her voice taut like the Muggle telephone wires they'd grown up seeing dividing the sky. "You've worked out the most logical time of day, the best spell for the job, you've got a note-taker-" Sky's face reddened, providing an unimpeded contrast against his short, no-nonsense dark hair. "-but how are you going to get in there? You don't know where it is for a start."

"That's why we're relying on you, dear cousin," Albus affirmed, biting his lips as not to awkwardly smile at her. Anxiously running her hands through her hair showed him that she was as invested in deciphering the mystery as he was but its excessive risks deterred her. She transferred her weight to one foot and back again as she weighed up her options.

"I'll be back in ten minutes," she eventually said. "Professor, may I use the loo?" When Ellis gave her a polite nod, she decisively strode to the door, her unexpected departure prompting Sky and Orville to give him perplexed looks. Whilst Rose was gone, he considered their plan - or lack of - warily. Was a Lilliputian step forward in terms of progress worth it? Did the end justify the means? It had to be if it meant they understood more about what they were dealing with.

Albus glanced at Kavyansh, studying his stocky figure. At breakfast today, his shirt and robes had been creased as if he'd slept in them and his hair practically reflected the knotted mayhem of his thoughts and speech. Potions was the subject he noticeably excelled at, amassing substantial numbers of house points for Ravenclaw, but he looked exhausted, the pits underneath his eyes burgeoning, the same plum colour as Ville's Sleeping Draught. The eleven-year almost looked emaciated. What on earth was happening to him? It was as if the fight had been knocked out of him over the past week. His brilliant blue eyes had become duller than a cloudy grey, making the Potter wonder if he'd been outside at all since the match.

"Thanks, Professor," Rose called out, wheezing ever so slightly, her arms tucked across her chest. "What?" she mouthed at Albus and Orville as they gave each other disconcerted looks. "If you want my help, stay with me." She withdrew two glass vials from her inside robe pockets which she hastily fastened when she caught him looking and deftly collected the lavender-hued Sleeping Draft. "Mine's about average so it should work."

Lounging on his stool and resting his chin on one knuckled hand, Sky queried. "What should work?" He concentrated his razor-sharp eyes on her, alert. "How are you dispensing that?" In the meantime, Ville shrugged at Albus as if to say 'Haven't the foggiest mate, just go with it', focusing on gathering purple liquid into his own vials.

A pillar of steam, a soft indigo according to the colour-chart poster on the main wall, billowed from the top of Kavyansh's cauldron, whistling shrilly. Rose spun around as she labelled her first vial, carefully inserting it into the Potion Master's rack. He'd set aside a designated area solely for their lesson's potions from their first Potions class.

"Mr Dewan, what spell did you use to complete your potion?" Professor Ellis pressed Kav, the strong implication of urgency in his tone. The boy moved sluggishly as if he was half-asleep. "Mr Dewan?"

Kav groaned, his face distorted, before foundering and collapsing to the cold masonry underneath. As Ville lunged towards him, arms outstretched as to catch him under his armpits, his fist knocked the cauldron to the floor, its thick, opaque contents fizzing as it made contact with the stone. A stunned lull in conversations was the result as their classmates turned to look, Albus' mouth ajar, startled. What had happened to Kav? Had the wandless magic hurt him in some way?

Ellis marched across from behind his desk, flicking his wand at the clumps of failed Draught with an instantaneous "Evanesco!", vanishing it as it hissed maliciously. "Students, bottle your potions and hand it in if you haven't already. Go to the Great Hall." He bent down to take the unconscious Kav's pulse and with concern evident in his weathered face, he cast a hazy Patronus, directing it through the castle's walls to where Albus guessed the Hospital Wall would be. The professor possessed cool level-headedness, which kept him and his classmates calm. Where had he gotten that from?, he puzzled as he followed the Potion Master's instructions if he'd been a shop-keeper for however many years. Over the low grinding and scraping of stools, he heard him speak again. "Miss Adelisa, would you mind finding Professor McGonagall? She's normally in her Transfiguration classroom on the ground floor at this time of day."

Ville had backed away, heaving his book bag over his robes. With a discrete gesture, Albus, Rose and Sky followed him into the frigid corridors outside, the air so cold their breaths gushed out of their mouths, glittering. Confirming their Ravenclaw classmates hadn't noticed them slip into one of the clandestine passages he and Rose had grown up playing imaginary games in over myriad summer holidays, he invited his cousin to explain where she'd disappeared to.

"James," she said, smirking, clambering up stone steps so worn they revealed a natural curve in the middle. Stuffing an iridescent material into her leather satchel, he gasped. Dad's Invisibility Cloak! Before his older brother was sent his Hogwarts acceptance lettwe, Uncle Ron would weave complicated stories of the Cloak in reverential and solemn tones, with him regularly ending as the hero in a daring twist of fate. Their dad would roar with laughter, wiping tears from his eyes. But he hadn't seen it personally until today.

"What do you think happened to Kav?" Ville asked, as their footsteps were dampened by the sound of the end-of-day bell tolling. "He looked really ill."

Sky mumbled his agreement. "I think he'll end up in St Mungo's. Grandfather wouldn't consult the Headmistress over a dead faint, Ville." They gathered around the top of the dimly-lit staircase, absorbing his words, Albus taking a deep breath as he pushed through the false wall, feeling his heart hammering against his ribcage. It would be just their luck to encounter McGonagall and a troubled Christine. Relief choked him. They'd made it to the third floor, the gargoyle guards flanking a barren expanse of brick wall at the bottom of the corridor.

"D'you think so?" Rose asked, scrutinising Sky's face. They hastened their pace when the raucous and boisterous chatter of the castle's inhabitants emanated from the walls. "Stop," she commanded, noisily fumbling around inside her satchel and producing her remaining vial. "Albus, d'you remember the Fire-Making Spell?"

He nodded, slightly bewildered by the question. "What are you doing with - that?"

"Basic principles of Muggle science," Sky explained. "The three states of matter, liquid, gas and solids. Rose is shifting the Sleeping Draught potion to a gaseous form because she's a bloody mad witch." She stuck her tongue out whilst he and Ville listened. "So we have to boil it in order to set up our first line of defence."

"You sound exactly like Professor Ellis," Ville muttered, aghast.

"Do we know the password to McGonagall's office?" Rose countered. "Sky, d'you know Wingardium Leviosa?" She set the glass vial on the floor. "Al, when he's lifted, do the Fire-Making Spell. It shouldn't take long, so when I say, cover your faces with your robes. Ville, come with me."

Albus and Sky formed a modest line, one foot in front of the other, pointing their wands at the vial filled with shimmering purple liquid. "After you," he said. They had no idea where Mullard or any of the other professors could be; they fiercely hoped that McGonagall and Ellis remained where they were. One of the portraits on the wall scowled at him.

"Harry?" it said.

Albus repeated its words as Sky cast the Levitation Spell. "Harry? Hang on, Valerie?" She'd flitted into one of the frames outside the Gryffindor common room the night of the match. "Rose, that's the password! It's Harry!" The vial hovered in mid-air, reminding him. "Incendio!" If it worked, why was the password Dad's name? A cylinder of seething flame materialised from his wand, vaporising the vial and its contents. A glistening fog expanded from where it'd been, looming menacingly over them.

"Cover your faces!" Rose screamed, before issuing a muffled bellow at the gargoyles. "Harry!" They tugged their robe sleeves over their noses and mouths, sprinting into the empty doorway and up the rising spiral staircase. "Bloody hell, Albus," she panted, wide-eyed. "That spell worked fine before."

Sky snorted. "I forgot vaporisation, naturally."

Had he lost control again? McGonagall's colossal bookcases greeted the foursome, the book spines glittering, some of their ancient lettering disintegrating and mouldering away in places. Their titles framed the pendulum that swung with mechanical monotony on the far wall, dictating Hogwarts' days. It had stayed the same as that fateful dinner on his and Rose's third day. Was it his guilty conscience or did the portraits, the few that weren't desolate canvases as their occupants had hurried off elsewhere, squint at him with deep-seated suspicion? Dumbledore and Snape's portraits were uninhabited, although Valerie had followed them into the sacrosanct heart of the castle.

They scanned the lower levels of the office for the Pensive before Albus stumbled upon it, tucked away in a corner, surrounded by a tall series of metal shelves, with hundreds of vials crowded into inches.

"Lumos," he whispered, angling his wand for a closer look at some of the decaying labels. One was marked with faint initials, an 'E' perhaps? A date - was it the year he was born? "I found it!" he called to his friends. Was his need to know worth the hefty consequences? Would his father be gravely disappointed if they were caught?

His hands quivering, he pressed the tip of his wand to his head, like he'd seen Dad do on many occasions in this office and thought considerably about the faltering memory. He'd pored over it so many times it'd become a meaningless jumble of images. Nothing. Was he trying too hard?

He persevered. It had to be there, somewhere. Jammed together around the basin, uncomfortably, their clammy and agitated faces were reflected in the undulating surface of the Pensieve. As his mind swam, the silvery strand of memory finally attached itself to his wand. The room careered, sending them tumbling into the circular basin. Its cloudy depths enveloped the foursome, the overcast October day forming around them as they landed, delicately, in the midst of the Quidditch pitch.

"God, I can see myself," Orville noted, a hint of disdain in his voice. "This is weird. Bloody weird. And that's grim," he snorted, elbowing Sky. Both of their past selves dissolved into the crowds filing out of the stadiums, yelling "Whoo! Gryffindor!" with exuberance. Muffled bickering reached their ears, from underneath the professors' and James' stand, escalating to mostly barbed words, sharpened to leave festering wounds. The memory momentarily darkened with the two disgraced Ravenclaw players' movements accelerating, their voices drowned out by a loud ticking noise. As abruptly as it'd happened, it stopped.

"Is that normal?" Rose demanded, almost fearfully, her gaze on the past-Albus and Kavyansh rushing to the aid of the duelling Ravenclaws, their faces lit up by the harsh red of jinxes. McDonald was sobbing, her shoulders convulsing.

Albus could see his own mouth moving but he couldn't hear anything. "No- I've never seen that happen before." The professors, especially Dupont, moved sluggishly and he caught himself screaming the cleaning spell, a horizontal line of fire cascading from his wand, constructing the outline of the fire daemon. Shifting his eyes to the formidable figure of Kav behind him, he watched him. His mouth or hands hadn't moved an inch. "What? But-"

"Transducium," came Sky's voice from behind the real Albus, a golden ellipse fluttering in mid-air, like a flag, poised.

Rose started fretting. "Albus-"

"It's any second now..." he insisted, watching the past-Albus mouth 'Bloody genius!' The charm quivered, before translating a singular word. Daemon. Flabbergasted, he clapped a hand to his mouth. Had he unknowingly addressed the daemon? The near-monosyllabic reciting of Latin words reverberated in his ears. The phrases that'd made his blood run cold filtered through the Translation Charm. "He called us. I have chosen. He called us. I have chosen."

Sky exclaimed as the memory evaporated to black, desperately jotting the translation down as the charm dissipated into nothingness. His cousin turned to him, her eyes full of unease. "It wasn't Kav. It was you." Horrified. A few seconds elapsed, yet the memory lingered. "Hold on… Should we still be here?"

Something in the distance shattered. They turned their faces to what should've been the exterior of the Pensieve, half-expecting the bony hands of McGonagall to take shape above their heads. Instead, a trickle of somebody else's memory metamorphosed the blackness into an ordinary street in the outskirts of a town, poorly lit by tawny-gold streetlights. "What the hell-" Sky cried out, before his voice cut out, almost in realisation.

Albus, Rose and Orville blindly looked around, their wands out, searching for whatever it was that their friend had seen before their eyes distinguished the row of houses facing the street. "Do you recognise this street?" Ville asked. Sky shook his head, his face a shade of alabaster. He had to be lying. "Lady… Gentlemen, let your eyes adjust to the dark. Rose, the Cloak. I'm not being caught now." Rose obliged, as thoroughly freaked out as Albus was, hurling the material over the foursome as they examined the street. It appeared every inch of the exquisite and unblemished semi-detached utopia his grandmother had spoken of dreamily, but there was something off here.

At last, Albus spotted it. The tiniest hint of ruby flares, exactly where the magical extensions had run thin, accommodating a strain somewhere. "The second house from the left," he whispered. The brick houses were silent, their lights turned off as if it was bitterly early in the morning in this memory. Their front gardens were modest, bordered by immaculate gates and smart hedges, but as soon as they stepped across the boundary of Number 23, the one he'd indicated, it was reconstructed into an unkempt and chaotic bramble, as if a later memory had been incorporated into this one. Whose memory was this? He was beginning to wonder, keeping Sky in his sights, studying the boy anxiously.

Did they have enough time in the Pensieve to work out who this memory belonged to? How long had it been in the real world? Had their scheme been unearthed yet? The questions clamoured inside his mind, imploring him to go on, engulfing his fears about himself and the daemon.

The front door, marked with yawning lacerations in one memory but undamaged in what he guessed was the original, allowed them to pass through like the Hogwarts ghosts. The curtains were drawn, as a blossoming young woman, shrouded in a Hufflepuff jumper, bounced a dark-haired baby on her leg, creating sparks with her wand. They surveyed the front room, filled floor-to-ceiling with vast numbers of books, sensing that something was about to happen. The wooden floorboards groaned upstairs, but the woman was unperturbed.

"Is this something we should see?" Sky asked, his face even paler than it was before, stepping out from the security of the Cloak. Albus regarded the woman's face with a resolute determination, searching for anything familiar. The stairs loudly creaked as if somebody frenzied had paced down them. A thickset man - Albus gasped - who was the exact likeness of a younger Professor Ellis fixed his eyes on the woman and her baby. But his eyes weren't the benevolent grey he recognised from Potions lessons. They were sharp, in a callous and sinister manner. Was this a different person?

"Cass," the woman beamed, contentedly, her pride melting the hard-faced man's anxiety. "Say hello to an illustrious Hufflepuff… Or will he be a Ravenclaw, like his dad-"

The window detonated, a merciless green flame erupting into the living room, hurling the small family across the far wall. Albus closed his eyes to avoid seeing the horror, the whooping of whoever was outside fracturing the air. It had been so...swift, like a methodical execution.

"Ellis, that's enough," Mullard's firm voice stated, unyielding, prompting Albus to look again as the memory dwindled into nothingness. The Northerner's hand was on Sky's shoulder, guiding him to the warmth of McGonagall's office. Rose stuffed her fist into her mouth to avoid saying something. He'd never been so grateful for it to end before as the sombre faces of Professors McGonagall, Ellis and Longbottom came into view. Who had that family been? Close relatives of Sky's? And whose memory had it been, if it was indeed his family? Albus knew of dozens of individuals who'd died in the First and Second Wizarding Wars but he hadn't noted any Ellises.

"Was he the only one there?" Professor McGonagall addressed Mullard, who nodded affirmatively. "Mr Ellis, I appreciate you wanting to understand more about what your grandfather told you at the start of term… But you should've asked me for permission before using the Pensieve. I won't punish you on this occasion - I gather the memory was enough." Sky continued to stare at the floor, Mullard's gnarled hand still clasping his shoulder. What had they just watched? Had the family been killed by the explosion? If so, what had caused it? Had it been Dark magic?

Professor Ellis earnestly traipsed to the edge of the office, intending to escort his grandson outside. The stunned group of Ravenclaws under the Cloak were only stirred into shuffling through the open doorway by McGonagall's stern command 'You may go now.'

The Potions professor waited until he'd steered Sky to the bottom of the spiral staircase before approaching the subject. Albus winced, feeling rude at listening in on what was undoubtedly something clearly personal to his friend. "I think you were unwise to go looking for what happened in the Headmistress' own Pensieve, Sky. You're too young to understand all of it." His grandfather took a deep breath, sighing. "I'm proud of you, regardless, but not today. Do you understand? You took advantage of your classmate's illness for your own gain."

Sky looked up, meeting the professor's eyes. "Is Kav okay?" When his grandfather didn't respond. "What ward in St Mungo's?"

"You know I can't tell you that, Sky," came the hushed answer. "Go back to Ravenclaw Tower. And...let Miss Weasley-Granger know I thought her Sleeping Draught was commendable despite being a little over-stewed. An exceptional fusion with Muggle science, demonstrating ingenuity. I'd go as far as to say it'd merit a strong pass in her Defence exam."