Note: I wanted to take a closer look at how the Black brothers grew into at least partially functioning adults – but then it turned into a ghost story. Very tentatively aligned with Still Life with Skull and They're Hiding Inside Me.

Warnings (for the whole story): physical and mental child abuse (on-screen, intermittent at first, fairly drawn-out and disturbing later on), some victim blaming, death by drowning, gaslighting, panic attacks, homophobia, and a suicide attempt by a teenager. This story is not only dark, but... yeah, it's dark.

Feedback: Yes, please. I love hearing from you :)

Blackpool, Part 1/6

They summer in Blackpool. It's a family tradition.

The summer Regulus turns five, he nearly drowns in the Irish Sea, or so they tell him. He can't even remember that day, but it enters the Black family anecdote collection just the same, told over and over, five hundred versions of the same event. They will smile and eat canapés ("Remember that one time when") or take a stroll along the seafront ("just tripped over air and fell off the pier") or taste rare whiskeys in front of the fireplace ("splash like someone dropped a -"). Maybe that's why he always moves so carefully now – like the world is made of slippery planks. His mother nibbles a praline ("At least one of the boys showed accidental magic that day. Of course, with him we knew since he was three"), while Regulus turns embarrassed and Sirius just turns quiet.

Regulus's own magic kicks in a few months later at Andromeda's birthday party, when he levitates a plate her personal house-elf drops. He feels sorry for stealing her spotlight, but she smirks and tells him it's all right.

Walburga doesn't lose any time. That next Sunday, she takes his first milk tooth and performs the ritual that binds his name to the tapestry, and the tapestry to him. It's the first time he's allowed in the drawing room, and it smells of mothballs and carpet shampoo and the heaviness of centuries. He knows his parents are talking, but he's not listening, too taken in is he with the vast maze that is his family. He understands more about his family in one morning than he has in all the years of his life put together, tracing the tapestry with his fingers, wherever he can reach, notes the regularities, the constellations, the recurrences. Fourteenth, sixteenth, nineteenth century. Regulus, Arcturus. They've been there before him, and they will come around again. He says the names under his breath. Sirius, Orion. Cygnus. Pollux. Altair. He's been told this before, of course, but he understands, for the first time, that one star doesn't make a night sky.

But many do.

His mother addresses him directly, and immersed as he is, he has a sixth sense dedicated entirely to that. He looks up, but she's not bitter today, no. She's happy. It makes him glow, too. "And when you die," says Walburga, "the tapestry will know before anyone else."

Behind her, seven-year-old Sirius pulls a face, and Regulus laughs.

Walburga tells the story differently after Sirius's first year in Hogwarts ("Remember that one time when Regulus nearly"), there's less pride in Walburga's voice, more we-should-have-seen-this-coming ("Of course, Sirius couldn't stay out of the spotlight for even a"); she butters a crumpet, gliding seamlessly into a different topic already ("Anyway, Orion, you were saying the Ministry ought to"), taking as given their full, quiet compliance with this revised history.

Surprise. Sirius is a Gryffindor now, and don't anyone forget it for even a second. "You pushed him off the pier!" he shouts over breakfast, and all hell breaks loose. He hasn't even been back twelve hours.

Regulus is the only one who remains quiet, for all the good it'll still do, eyes fixed on his soft-boiled egg. That's not how it happened, he tells himself, Sirius is lying, he wasn't pushed, he fell, and even if, it was a test.

It's the first day of the summer holidays, Regulus's birthday and he's eleven. It's a day he's looked forward to since Easter because Sirius home means a break from boring calligraphy lessons, it means laughter and exploring the dusty attic and vertical Quidditch in the garden and the sort of games that their mother claims turn her hair grey. (The brothers may or may not have turned it into a competition – but alas, their mother's hair remains as thick and black as ever.)

Instead, Sirius spends the rest of the morning in the study with Father, and the rest of the day in his room, and except for the tight press of Walburga's lips, it's as if Sirius hasn't come home at all. Regulus opens a pile of birthday presents and letters under the hawk eye of his mother. They're exquisite and thoughtful; a week later, he hardly remembers them. Only two stick in mind: The Hogwarts letter, perched on top of the pile, and cousin Andromeda's present, wrapped in a glittering star chart. It's a diary and so plain it looks almost Muggle, but it's not.

("It's bigger on the inside," she tells him later, "You'll never run out of pages. And you can teach it a pass-phrase so no-one else can read it. Think of something clever, Reggie."

"But what do I write?" says Regulus. For all the calligraphy lessons in the world, he doesn't think enough happens in Grimmauld Place to warrant writing down. "Things you learn," says Andromeda. "Things you experience. Things you do not wish to forget." She winks.)

He decides to humour her – besides, Sirius has the same diary, got it from Andromeda when he turned eleven the November before last, and Regulus likes having the same things as his brother. He makes up a pass-phrase ("Toujours Pur"), and he writes down that story he doesn't quite get, that summer day he can't remember. Five hundred versions of the same anecdote.

He supposes the diary must be magic, because the next time he opens it, all the stories have turned into just one: The one his mother has been telling all the time ("Remember that time when Regulus tripped over air –").

They go to Blackpool again that summer, Regulus and Sirius and their parents, and Narcissa and Andromeda and their parents, all except Bellatrix, who says she is busy with her volunteer work, and Regulus could swear his aunt and uncle breathe a sigh of relief. All the more space, and slightly more peace, in the Black summer residence, which doubles as a 19th century hotel, or rather: It's a 19th century hotel, except the hotel owner doesn't know it doubles as the Black summer residence. Does keep it tidy, though.

The Blacks enjoy the proximity of Muggles, but not to mingle, on the contrary: Life is a work of art, and theirs is full of sharp contrasts, discordant notes. They enhance the differences.

Black Pier is private. You have to be a Black by blood or marriage, or you'll just walk past it. That's where they are now, Sirius and Regulus. Ten p.m. has come and gone, it's really rather shockingly late, and even though Regulus can feel the tiredness pulling at his bones, daring him to bunch up his cloak and take a nap on the wooden boards, he's a bit giddy - too many raspberry lemonades and gummi flobberworms will do that to an eleven-year-old - and no-one has been shouting at them in two days, largely because it's so much easier to stay out of their parents' hair when they're here.

It's a rare warm summer's night, the sky still in bright twilight. If the brothers are lucky, the stars will come out before they are called to bed, before the still nearly full moon rises in the east and obliterates everything in its wake. Regulus is already fixating on a point over the see, far away in the west, where he knows his namesake star is hurtling towards to horizon, chasing after the setting sun.

To pass the time, Sirius has his diary open, and he is trying to bewitch a quill to draw the sea, the rippling, foaming, swirling waves below them. It'd be a feat and a half even if he drew it himself, Regulus supposes. Not happy with the accuracy, Sirius flips over a new page occasionally.

"Just wait till you get to Hogwarts," says Sirius. "Those winter nights are proper dark. Not like stupid London. Pitch black, and long. Winter term is brilliant for Astronomy." He shows no sign of tiredness. "Of course, it rains."

Only Sirius could sell Scottish winter as a feature. To be fair, very nearly everything he's said about Hogwarts has made Regulus want to go even more. Hard to believe it's just two more months now.

"Terrible," says Regulus with all the sarcasm a newly eleven-year-old can muster. "To imagine a place where it rains constantly! What is this, Britain?"

Sirius bops him. "I hear the damp is worse in Slytherin," he says, watching the quill dance over the page. "Underground, see. You'll grow fungus on your hair and algae between your toes."

Regulus remains still. He can't imagine finally going to Hogwarts, only to be separated from his brother. Coincidentally, he also can't imagine ending up anywhere but in Slytherin. Because, come on, Sirius's sorting was a fluke, wasn't it?

"Underground," he says. "Exactly. Gryffindor tower is far closer to the weather. Besides," he adds uncertainly, "Cissy and Andy have very good hair." He hasn't checked their toes, though. Blast. Maybe he should ask the Sorting Hat for clarification first –

A shudder runs through him as he imagines the Sorting Hat saying, "Questions already? Better be RAVENCLAW!" No, he's just going to sit still. Is sitting still a Slytherin trait? Is begging? Sirius says he tried that. Didn't work. So maybe begging is out.

Above them, the first faint stars blink into existence. But the twilight remains, an eerie glow that seems to come from the sea itself. Of course, this is the Black Pier, been in the family for generations. Who knows what magic it might have soaked up?

This is probably perfectly normal.

"This is weird," says Sirius, and Regulus is secretly relieved.

"It is, isn't it," says Regulus. "It's not just me?"

Sirius, already sat at the edge of the pier, crawls forward, hypnotising the luminous water. It looks extraordinarily dangerous from Regulus's point of view, but then, he did almost drown once.

"Hm," says Sirius, and leans in.

Regulus yelps. "You'll fall!"

"Shall I tell you a secret?" says Sirius. He turns around and winks conspiratorially. "My mate James taught me how to swim in the Great Lake. He said it was ridiculous, not being able to swim. Said it was old-fashioned and stupid."

"But that's – that's a Muggle thing!" says Regulus. "Don't let Mother find out!"

"Promise," says Sirius. "I'll just drown quietly like a good little Pureblood." He returns his attention to the water.

"We don't drown," says Regulus. "We float. That's how Muggles used to tell, isn't it?"

Sirius, of course, disregards his compelling logic. "I really think you should see this," he says.

Torn between curiosity and a sudden, embarrassing, quite all-consuming terror, Regulus crawls forward, inch by inch, until he's flat on his stomach, peering over the edge.

There's a body in the water.

Regulus is quite glad he's lying down already, because he is just about ready to keel over. He jerks back, but too late, that image is burned on the inside of his eyes, already as familiar as the night sky: A child, pale and luminous, drifting face-up in the Irish Sea, eyes wide open and dark as bruises, features blurred like an unfinished watercolour.

While Regulus quietly contemplates whether to start hyperventilating, Sirius remains unfazed.

"Relax, it's just a ghost," he says. "There are plenty of ghosts at Hogwarts."

"Yes, but –" says Regulus, collecting his thoughts. "But this one's dead!"

He hasn't encountered many ghosts in his life. Grimmauld Place is warded against them, from the top of its roof to the last corner of its ramified cellar, otherwise that house would attract ghosts like nobody's business.

"They're all dead, Reg," Sirius points out. "In fact, those at Hogwarts all died quite horribly. They're still nice people." He pulls a face. "Except the Slytherin ghost, he's a bit of a jerk."

"But this one's proper dead," says Regulus. "He doesn't even move."

Sirius considers this, then lies down flat on his stomach and extends a hand to the surface of the water. It doesn't quite reach, but the odd light – and Regulus knows now it's the ghost's luminous soul – engulfs Sirius's hand.

"Hey there, buddy," says Sirius. "You look like you need a friend."

"Oh god, don't touch the dead child," moans Regulus. Sirius might think ghosts are harmless. Regulus just assumes there's a very, very good reason Grimmauld Place is so thoroughly warded against them.

Doesn't mean he can look away. The ghost turns his head, slowly, slowly, and those lifeless, bruised eyes lock with Sirius's. His face, blurred as it is, changes – there's something like alertness now. Something like recognition. The ghost lifts his hand and tries to grasp Sirius's, but it passes right through. This, apparently, causes him great distress, judging by what is unmistakeably a sob. Ghost water splashes as he tries again and again.

"It's okay, it's okay," says Sirius. "You just have to imagine. Close your eyes and imagine you're taking my hand, I'll help you out."

It's weird. "Soothing" is probably the last word Regulus would use to describe his brother's typical demeanour, but the ghost child calms down somewhat. After Sirius has helped a very distraught ghost scramble onto the pier, he turns to Regulus and whispers, "He's not very good at this, I don't think he's been dead very long."

"But that's –" says Regulus. "That's so sad. Isn't it sad? Should we tell someone?"

The ghost is still crying. He's sitting between them now, gasping for air, soaked and pale and translucent. He's wearing wizard robes, that much Regulus can make out, but the details escape him. Pale face, dark hair like seaweed, rail-thin body hunched over, making him look even smaller than he is.

Regulus tries to remember what he learned about ghosts: Pure imagination, all mind, no body; they have to make an effort to keep up their appearance. Maybe this child can't, or doesn't know how. Maybe one day he'll blur into fog.

Through that translucent head, Regulus can see Sirius make a worried face. It's very far from his usual face. "What happened to you?" he asks quietly.

Another sob. "Fell," says the ghost. "I think. Slipped and fell. Clumsy. I couldn't – I couldn't –" He shrugs slightly. "Drowned."

Something constricts in Regulus's throat. It's just a word, he tells himself. And drowning is just water.

"Do you remember when?" he says, and he can see Sirius has the same question. Maybe someone's missing this kid.

"Ages. A hundred million years," sniffs the kid. "So alone."

Sirius holds out a hand. The child stares at him blankly, but Sirius just nods. "Imagine," he says. And the kid reaches out and sort of grasps it. "Almost," he says.

Inspired, Regulus reaches for his other hand. The touch isn't quite a touch, it's a cool breeze in the rare summer heat – a reminder of how things usually are. Like stepping from the blistering street into cool, dark Grimmauld Place. And like in Grimmauld Place, he has to be careful, controlled, or he'll fall right into that frigid presence and all pretence is lost.

The ghost looks down on his hands, then turns to Regulus. "I'm sorry I scared you," he says, his voice slightly less wobbly. "But I heard you talk about Hogwarts. Are you two wizards?"

Regulus nods. "Are you?"

"There are never any wizards or witches here," says the kid. "And the Muggles always get so scared when they see me, so I try not to be there – I dissolve – I'm there but I'm not and it's scary - "

And there he goes again.

"What's your name?" says Regulus.

"I dissolve," says the child. "I'm water. I'm a light on the waves. I don't know! What's yours?"

"Regulus," says Regulus. "And this is my brother, Sirius. Like the stars?"

"Regulus," the child whispers under his breath. "Sirius. Like the stars." He repeats the names a few more time, like he's trying them on. "Will you be my friends?"

He looks at them, and blurry as he is, there's so much hope in that lonely face. Regulus can't help it, he's still a little sceptical. He's never had a ghost friend. Or any friend, apart from Kreacher, really.

"Course," says Sirius. "I love making friends!"

He has to nudge Regulus, who mutters his assent.

The child smiles.

"Brilliant," says Sirius. "We're supposed to visit the haunted house up in Fleetwood tomorrow and it's boring, you should come! It'll be a million times better with a proper ghost –"

"Oh, there you are," calls a voice, distorted through distance and the bustle from the seafront, and the brothers turn their heads guiltily. On the end of the pier is a woman, a mere silhouette, tall, imposing, and worst of all, advancing quickly. She must have seen the ghost, or at least the light.

"Mother?" mouths Sirius, a worried expression on his face.

The child squeals. "I dissolve," he murmurs. "I dissolve, I dissolve –"

"No, wait," says Sirius. "Stay! That's Andromeda, she's harmless –"

But the ghost falls forward, into the water, expanding, thinning out, like a dust cloud. Out of reflex, Sirius scrambles up and grasps for him. This achieves exactly nothing except that he kicks his diary into the sea, and Sirius curses, using words that would have earned him a scouring charm straight to the mouth, had Walburga listened.

But the ghost is gone, leaving nothing but foam on the waves and massive confusion.

Sirius stares at the green waves that swallowed his diary. "Well, that was odd," he says. Eventually.

"Think he'll come to Fleetwood tomorrow?" says Regulus.

Sirius just shakes his head. A flick of his wand summons the diary, but it's soaked, of course. He flips through the pages, tries to get them to unstick, and his fingers go grey with diluted ink. He's still staring, like he stared at the sea a moment ago – like he's trying hard not to remain attached to a gone thing.

"Oh, don't worry about it," says Andromeda, who has finally caught up with them. "It's protected against all sorts of stuff – just leave it alone, it'll soak up what it needs and expel the rest."

"Soak up what it needs?" repeats Sirius. "It's a diary!"

"Yes, and a diary keeps things, doesn't it?" says Andromeda. "By the way, your mother sent me to find you. Apparently it's your bedtime."

"She said we could watch the stars," says Regulus, trying out a tiny dose of defiance. It's easier with Andromeda than with their mother.

"And?"

"They're only just coming out!"

"Well then," says Andromeda, a twinkle of mischief in her eyes. "Seeing as I am a responsible adult, I'm sure she won't mind if I let you stay for a little while longer."

Sirius pokes his tongue at her. "You are so smug for having turned seventeen, aren't you," he says.

"Cheeky, my favourite Gryffindor toerag," says Andromeda.

Sirius grins. "Slytherin hag."

"You want to watch stars, ickle firstie? Let's see what you've got. Where's Andromeda?"

"Looming dangerously above us," says Sirius. "Come on, is that all you've got?"

"Orion?"

"Ah," says Sirius. "Trick question. Other side of the planet. Phew!"

"Along with your namesake, so I wouldn't count my ducks just yet," says Andromeda. She fires off a list – their entire family, along with a number of stars that no-one has been crazy enough to use as baby names yet. Deneb. Antares. Cassiopeia. Camelopardalis. Boötes. Sirius gets them perfectly. Regulus is good, too, if a bit shaky on the finer points.

The first time they falter is with Altair. Sirius squints up at the sky.

"I always forget that one," he says. "To be fair, Great-Uncle Altair was one ugly troll. His portrait always pops into my mind when I hear the name and then I get distracted by the lichen."

Andromeda snorts softly, ladylike. "Regulus?" she says.

"Great-Uncle Altair wasn't an ugly troll," says Regulus, "he had a very serious condition –"

"Indeed. Turns out you can't mainline Gillyweed the way he did and expect to retain your youthful complexion," says Andromeda, and Sirius snickers. "The star, though. It's one of three, look? Deneb, Vega, and Altair. The summer triangle."

As she points them out in the sky, one hand on Regulus's shoulder, there's a sort of muffled yelling in the distance, yellow flashes of blatant localisation spells on the Muggle beach. "Oh, where is that infernal –", and when they look up, they see Walburga striding towards them on the pier.

"Whoops," says Andromeda. "Guess I was supposed to take you home right away. God, but their parlour games bore me to tears."

Regulus swallows as their mother approaches. He swears she can make herself about twice as heavy as she is, just by striding in anger, each step of her delicate pointed leather shoes jolting the pier. His brother looks about as relaxed as he feels.

"Auntie Walburga," says Andromeda in her most sincere voice. "I'm sorry, I forgot the time – your sons are such a delight, have I told you?"

Walburga absolutely, positively, looks like she is going to explode. Messily. With casualties. Her quick hand is hidden away just underneath the surface, but Andromeda is beaming at her, and that is a boundary Walburga has not yet crossed.

"It's hours past their bedtime," she scoffs. "So worried – irresponsible – boys, come with me."

Sirius picks up his diary, still dripping sea water, but Walburga snatches it out of his hands, flips through it. The heavy parchment is holding its shape, doesn't tear despite her less than careful handling, but the ink is still running off the pages in thick droplets. Not that the diary would show her anything but gibberish, since she doesn't have the pass-phrase.

"Such a tasteful gift, Andromeda," she says sweetly. "But perhaps not for a clumsy boy like Sirius. Ruined already, I see." It passes whatever superficial inspection she is administering, and she presses it back into Sirius's hands.

"Oh, that's quite all right, Auntie Walburga," says Andromeda. "Diaries are more for writing than for reading, anyway." She winks at the boys, then links her arm with Walburga's, leading her away from the sea. "Now, you were telling a fascinating story about the end-of-year school governors' meeting –"

The brothers set off after Walburga and Andromeda, hanging back for as long as they dare. Still, Sirius raises a finger to his lips, and Regulus understands: The ghost is a secret now, not just tonight, but forever. The way their parents have warded Grimmauld Place against ghosts, they will exorcise the Black Pier in a heartbeat, and then where will that little drowned boy go?

Regulus mouths the word under his breath: Forever. He catches a last glimpse at the sky above. Stars are forever. Ghosts are forever, too, he supposes.

A hundred million years, at least.

The ghost doesn't come to Fleetwood the next day. In fact, even though they spend many more evenings on the Black Pier, they don't see hide nor hair of him for the reminder of their holidays. Sirius watches the waves like a hawk, but nothing – no light, no shine, no drifting child. Regulus starts to think the ghost is a figment of their imagination, a false memory, or maybe a mirage, a magic reflection that turned up hundreds of miles from where it belonged.

Meanwhile, Sirius's diary is starting to dry out, but it still leaks occasionally. Every morning, they find it sitting in a puddle of ink-grey water, and whenever Sirius tries to write in it, the words branch and blur and vanish.

The next time Walburga tells the anecdote of how Regulus nearly drowned when he was five, they're most of the way through their farewell dinner. They're the only party in the hotel's glass-roofed dining hall, beads of sweat on their foreheads, warm evening light dancing on the cutlery and refracting in the decanters full of port. Only a day now until they're back in cool, shadowy Grimmauld Place.

Of course, remarks Walburga over her coffee, Sirius just tripped over nothing, clumsy boy, fell into his brother and off the pier Regulus tumbled, oh those rambunctious boys, you wouldn't understand, Cygnus, with your three charming girls; mine are quite the handful, did I say something funny, Andromeda?

Andromeda smiles into her gold-rimmed coffee cup. "Forgive me, Auntie," she says. "It's just such a riveting tale," and Regulus doesn't know where to look. He feels, with practised ease, that his heart picks up speed, that his ears resonate with the distant rumble of the sea – but that must be the coffee, he thinks.

After dinner, Regulus and Sirius are sent to an early bed. The room they share in the Blackpool hotel is a plush affair with a view of the seafront, overlooked by a large and frighteningly ugly painting of their late Great-Aunt Vulpecula, who is ever so cranky. Regulus reckons it's because she has to pretend to be a Muggle painting for the majority of the year. Sirius says she's just a miserable old hag. Either way, they ought to have guessed sooner – but it has taken them eight holidays in Blackpool and many an inexplicable telling-off by their parents until they figured out the old biddy is spying on them, too.

Changing into his pyjamas, Regulus is half ignoring, half composing a head full of thoughts that he needs to share with his brother. Because, frankly, what is it with these anecdotes his mother tells? He feels like he should know this story by now, having nearly died in it, but every time, it's like he hears it for the first time.

He drops his braces to the floor, not on purpose, he's just on edge, but it's still loud, and his great aunt turns her painted head towards the commotion, fiddling with an old-fashioned ear trumpet. Suddenly he can't help himself anymore. "Seriously, she's about two hundred," he whispers as softly as he can, "can't she just take a nap now and again?"

Sirius, already in bed and thumbing through his diary, which Vulpecula is fortunately too blind to see, graces him with a soft laugh. "Tomorrow," he mouths.

Regulus flops down on his own bed – if nothing else, he's definitely dramatic enough for Slytherin, even if the thought of his impending Sorting fills him with clammy dread. But instead of sleeping, he grows more restless by the minute, all senses assaulted, unable to ignore a thing – the evening sun is lighting up their room like a Quidditch pitch, despite the threadbare curtains, and between the thick carpet and the lush pillows and the luxurious sheets, it's stifling hot. The stale air smells of dust and mothballs and the bag of Every Flavour Beans melting into a confused clump somewhere in Sirius's suitcase. Even the soft sounds of parchment and quill from the other bed feel alien and too, too much, like he hears them with his fingernails.

Sirius's diary is full of wonders, but Regulus's own is dreadfully bare. He hasn't looked at it in weeks, but since sleep isn't coming, he gets it out, intending to pen the anecdote his mother told over dinner, that thing that keeps eluding him. Maybe that will keep the room from closing in on him.

To his mild surprise (it really is rather ridiculously warm, and his brain feels overwrought and stupid), tonight's story is already in there, and he re-reads his words, almost a memory, written in his own careful script: How Sirius tripped over air and fell into him. How he dropped off the pier like a stone. How his mother lifted him out of the water with a levitation charm, Vanished the water in his lungs, wrapped him in a warm wind to dry him and stop the shivers.

Regulus reads it six times. He looks at those words until they blur and dance on the page, and makes an honest attempt at remembering that day. He thinks back to the summer he turned five. He thinks back to pumpkin ice cream cones and gummi flobberworms and the Black Pier in the setting sun. He thinks back to the smell of fried fish on the beach, of salt and algae on the pier. But they come to Blackpool every year, how could he possibly pick out one summer, one single day -

He reads the words again, careful cursive, all joined together, they link up, form a ladder, no, a thread, and he pulls, and he pulls: One summer. Three days of sun snatched up in three weeks of overcast skies. One of those days is gone forever, cut out like weed from a garden, but now, like weed, it has spread.

He's been here before, he suddenly knows, in those forgetful moments before he sleeps or after he wakes, on the trailing edge of a dream, when he is calm and cold and weightless, and there's a pressure all round his chest and arms and legs, and the ceiling looks wonky, as if he sees it from the bottom of a lake.

Adrift again, his thoughts turn smooth and shallow, everything tilted towards that hole in his memory, that single death-shaped day – and for once, it feels easy, the easiest thing in the world, to just let go, let everything slide and crash and fall –

Sirius thinks he's scared of water. Regulus knows he's not scared enough.

He's flat on his back now and it's dark and he breathes, still, against the pressure, as if millions of litres of water are pushing his chest down.

The sound of feet padding over the carpet. A creak of the window and air flows, finally, carrying the laughter of tourists and the roar of the sea. A dent in his bed as someone sits down. Soft press of a hand on his chest, right over his runaway heart – and he can't even say why that helps, maybe he's not being compressed, maybe it's the opposite, maybe he's just expanding now, like a balloon, like a deep-sea fish brought to the surface - until the water around him retreats, coalesces into just a mattress and humid air and tangled sheets, and he doesn't have to work so hard just to breathe anymore.

Oh, the portrait will definitely tell on them, but there's nothing he can do about it now.

"Nightmare?" says Sirius.

Regulus feels like he's run a marathon. Yet he sits, snapping up like a flick knife, one more second on his back and surely that heavy mattress will swallow him whole. His diary tumbles to the floor. "Yeah," he breathes. It's close enough to the truth.

"Budge over," says Sirius, and settles in next to him. "Here, this'll cheer you right up."

Regulus is conscious of his sweat-soaked sheets, his still-racing heart, but Sirius doesn't seem to mind. He drapes an arm around Regulus and flips through his own diary. It's darker now, only the Muggle lights outside their window illuminate the room. Still, Regulus can see that Sirius's diary has recovered from being dropped into the sea: The ink is back in place, crisper than before, the writing, the drawings, the maps; the parchment is strong and smooth.

"That's brilliant, Sirius," he mumbles, head lolling forward. He really is quite tired, after all. Sirius's diary is open on one of those drawings he made when they were out on the pier two weeks ago, when he was trying to enchant his quill to draw the waves all by itself. Those lines are moving now, faint ripples in a soft breeze.

"No, here, I mean –" says Sirius, then thinks for a moment before pulling Regulus's neglected sheets over both of them, and for a moment Regulus can't see a thing. Then his eyes adjust.

"Oh," says Regulus.

"Can you see it?"

In the utter darkness beneath the sheets, there's a faint silvery glow coming from those pages: A shine on the waves, a light on the water.

There are maybe thirty of these wave drawings, one after the other, and Sirius turns the pages slowly. It's on every page. Just reflexes on the waves, seemingly random, wherever the rippling currents would throw them.

"How did you do that," breathes Regulus.

"Didn't," says Sirius. "Look."

Sirius is thumbing through the pages now, like one would a flip-book, and the reflexes run together. Mesmerised, Regulus thinks of constellations: Two-dimensional shapes to make sense of a three-dimensional sky.

And just for a flash, there's a shape in the water: Eyes like bruises, hair like seaweed, a blur of a face. Like walking past a mirror in the dark.

They stare down at the undulating waves, and just for a heartbeat, the ghost stares back.

To be continued.