Notes: So here we go. Last part. Definitely the last part. No hidden chapters this time. Did I mention I wrote like six different endings? Well, this is number seven. It also got a bit… psychedelic 'round the middle, but that's what you get for just drinking any old potion Voldemort's left lying around, I suppose. Thank you so much for all your wonderful feedback! Writing this story has been very rewarding (and also, super intense, and creepy at times. As fun as the whole process was, I'm looking forward to having my brain back ^^) Looking forward to reading what you think, and feel free to correct my abysmal French.

Blackpool, Part 6b/6

"After me, I think," said Dumbledore, and he walked through the archway with Harry on his heels, lighting his own way hastily as he went.

Joanne K. Rowling, Harry Potter and The Half-Blood Prince

The summer Regulus turns five, his brother Altair nearly drowns in the Irish Sea.

Regulus's memories of that day are jumbled, scattered, a puzzle broken into too many parts. He remembers the eerie silence after the splash, when the sea turns smooth and flat like a mirror; stare down and a face stares back up - then rushing, screaming, buzzing, Sirius's raw magic outshining the summer sun. He remembers his Uncle Alphard shouting. Today is not the day, Walburga. He remembers Altair's robes drying off the side of the pier, a towel round his narrow shoulders, Muggle comfort for the Muggle changeling. He remembers his cousin Andromeda hugging him tight.

They all get ice creams after, and red lemonade. Regulus remembers drinking thirstily from his cup; it spills all over his hands and he cries. Curious, the things a child will remember.

Walburga tells so many anecdotes, but not this one. They will smile and eat canapés ("Remember when Sirius walked straight into a Thestral at the Somerset race?") or take a stroll along the seafront ("Just opened the gate and wandered off.") or taste rare whiskeys in front of the fireplace ("And little Regulus right on his heels, of course; nearly took a hoof to the face."). But she doesn't tell that one. She doesn't talk much about Altair at all.

When Regulus asks, she tells him it's not real.

The first time Regulus dreams of water is during the long, slow summer of 1969. One night in July, he wakes disoriented, exhausted, alone, and thirsty. Weird noises bounce all over Grimmauld Place, static and faraway voices jump from wall to wall, like skipping stones – disturbing the waters, he thinks groggily. No wonder he's awake.

It's usually a safe bet that any weird noises will have something to do with his brothers, so he goes to look for them. But Sirius is gone from his room, and so is Altair, so Regulus gathers all his courage and walks up the spooky narrow staircase to the roof of Grimmauld Place, taking great care to skip the two Vanishing steps. The door at the top opens with a creak.

They don't even look up. It's gone three in the morning, yet here they are, Sirius and Altair, fiddling with a weird, bulky thing. It looks to Regulus like a fishbowl got stuck in a box, and it seems to be the source of the noise. They're talking among themselves in low, excited voices.

"Can I play, too?" says Regulus.

Finally, his brothers startle, but it's just him after all. They look at each other, and then, annoyingly, they speak French, and Regulus only knows enough French to know they're talking about him. Penses-tu qu'il peut garder le secret? says Sirius.– Il garde toutes les secrets, Sirius-comme-l'étoile, says Altair. Laisse-lui regarder.

"Sit down," says Sirius with a smile Regulus can't read – like he's sitting on the best surprise in the world. "Have a hot chocolate. And shut up, we've almost got it working."

"You've got it working all over the house," says Regulus. "The metal rails were singing at me."

"Whoops," says Sirius. "Guess the amplification charm was spread too wide…" He fiddles with the antenna. Below them, Grimmauld Place stops vibrating.

"Think that's it," says Altair. "Put some charge on the wires, and loop it round infinitely, that should do the trick." Altair has a frightening grasp on the mechanics of magic, for someone unable to do any. Regulus frequently forgets he's a Squib.

Sirius taps the box with his wand and an excited incantation. The screech of feedback almost deafens them, but then figures dance over the glass bowl, and a tinny, sonorous voice fills the air.

"What's this?" says Regulus. "What's happening?"

"Guess!" says Altair. He points at the moon above them without even looking, while he's fiddling with a rotary knob. "Something's happening up there!"

Regulus tears his eyes away from the fascinating fishbowl box to squint at the moon instead. It looks perfectly ordinary: A waxing crescent.

"Told you, we should have taken Father's telescope," murmurs Sirius, who seems disappointed he can't see what's happening on the moon with his own eyes.

"Let me catch you in his study again, and I will give you a clip round the ears," says Altair. "Have you no sense of self-preservation?"

"Says the one who brought a Muggle telly into the house," says Sirius.

In Regulus Black's humble opinion, neither of his brothers has any sense of self-preservation. Besides. Muggle telly? Telescope? Moon? "What?" says Regulus. "What's happening?"

Sirius lays a friendly arm across his shoulders and whispers directly into his ear. "The Muggles are on the moon!"

That clears up exactly nothing. "The Muggles –" Regulus begins.

"They're walking on the moon!" says Sirius. "Well, in a bit," he concedes. "Unless something explodes, or, or, this telly contraption collapses into a black hole. Were you sure about the vacuum spell, Altair?"

"It's a cathode ray tube," says Altair. "It needs a vacuum."

"All right, all right, just pointing it out," says Sirius.

Regulus, however, is still stuck on their previous conversation. "But that's way too far to Apparate!" he says.

"They're Muggles, silly," says Sirius. "They can't Apparate!"

"Are they Flooing?" says Regulus. "No, that's impossible, you'd have to go there to build a fireplace. I know! House-elves! They can do amazing things, I bet they can Apparate there."

"Wanna ask Kreacher and find out?" says Sirius with a mischievous grin.

"They built a ship that can fly," says Altair, before Sirius can dare, double-dare, and double-dog-dare Regulus into doing something extremely stupid. Again.

Still. Something in Regulus's mind stubbornly refuses to wrap itself around the entire concept. "But they don't have magic," he says.

"They don't need magic," says Altair.

"You just said they built a ship that can fly!" says Regulus. "Like, how –"

"…You're thinking of a sailing boat, aren't you?" says Altair. "It's a rocket. Like firework, just bigger. They fling it upwards with a giant explosion…"

Once again, Regulus feels left in the dust by an explanation from one of his brothers. "Oh, now you're just pulling my leg," he says.

"Shut up, shut up, don't question it, just look at the pretty pictures," says Sirius, who's had his ear close to the loudspeaker during their discussion. "It's starting!"

And Regulus sits, nested in-between his older brothers, sipping from a cup full of hot chocolate. As they watch Neil Armstrong take a step that is both small and giant at the same time, he feels his paradigms shift: Because the sky is not just a tapestry, a backdrop for his family to shine.

The sky is a thing he can touch.

"Whose idea was that?" says Orion the next day.

"Mine," says Altair. "I heard about the moon landing at – at school." He's not allowed to even mention the prestigious prep school he's attending. Chances are, in a few years, he's going to be the first Eton alumnus in history whose parents were too embarrassed to even sign the enrolment forms. Uncle Alphard had to fix it all.

"And who charmed that Muggle contraption?" says Orion. "Certainly not you."

"I did," says Sirius.

"I told him how," says Altair stubbornly. He hates seeing his genius ignored.

"That seems unlikely," says Orion mildly. Any other parent, Regulus thinks, might have been impressed by their brilliance – Altair understanding how cathode ray tubes work, Sirius charming one to pick up the moon landing - but Orion chooses to gloss over one kind of brilliance, and flips the other on its head.

"And who," says Orion, "sat down to watch, like an overly excitable Muggle?"

Altair and Sirius look at each other.

"We made him," they say, "We told him it's fun," they say, "We hid his stuffed dog on the roof," they say, "Please, Father, he's only eight."

Orion sighs, as if he can't believe he even has to concern himself with these mundane matters, Muggle antics, underage magic, and his sons' stuffed toys.

Maybe it's because Regulus is so very tired, after the night spent on the roof. Tired and thirsty and wanting to leave. His brothers are crowding him, as if to hide him, but he's small and slight enough to step forward through the gap they leave.

A small step, he thinks. A giant leap.

Then he thinks of powdery moon dust, of stark shadows and bulky white space suits, and he says, "I did."

If they didn't want you to go the Gryffindor, reasons the Hat, why would they name you for a lion?

Regulus thinks about his answer for so long that the Hat threatens to put him into Ravenclaw just for that.

Because they think the sky is theirs, he tells the Hat. And the moon and the sun and the stars. All theirs. And no-one else can claim them.

And you? says the Hat. Do you think they're right?

Neil Armstrong walked on the moon, so there's that, thinks Regulus. I'm thirsty, I'm tired, I'm done. Just pick a house and I'll go.

The Hat is silent for a long, long time, until Regulus is tempted to just walk away, give this another go tomorrow.

You're not done yet and I'm sorry, the Hat says eventually. I know you're tired, I know you're thirsty. Know that, wherever you go, you will find water at the end.

Another long pause.

But you don't have to do it alone.

The Hat is right. There's water wherever Regulus goes. It's over his head, suspended in the eternally overcast Scottish skies, under his feet in the rain-soaked grounds. It's in the walls, rushing through pipes. It's in the showers after Quidditch. It's in the frigid Black Lake where Sirius and James teach him how to swim. It's in his blood, and in his mind, and in his dreams, until he's thirteen and the Black family curse catches up with him.

Idiot, says Sirius, and that's about it.

Do you believe in fate? Regulus writes in a letter to Altair, later. If we could go back to the start. If we could do things all over. Do you think there are some things we just can't escape?

I believe Divination is not for you, writes Altair from Eton. I believe your path is shaped by your decisions, not the leaves in a teacup, or the movements of the planets, or the musings of a Sorting Hat.

But I do believe in fate, Altair writes. I believe we fight her with every decision we make. She fights back, and she fights dirty. So we fight dirtier.

They give Regulus Dreamless Sleep Potion so he won't feel like he's drowning all the time. So he won't have to gasp for air and push back against that terrible thing that compresses his heart. This potion is purple, tastes of blueberries and tea, a cup full by nightfall, every evening from now till he dies. A cup, and another, and another.

Some nights, it seems to turn into something else, Sleepless Dream Potion, he calls it. Those nights, he feels restless and unreal, like he's living a fictional life, an afterimage, an echo, where nothing fits or makes sense. He goes to the Black Lake, then, and skips stones on the mirror-like surface under the stars. Lupin is there sometimes, too, driven outside by his own monsters. They threaten to kill him, once a month, like clockwork.

Regulus tells him about Neil Armstrong, who walked on the moon, and it turned out to be just another rock.

Fate takes on many disguises, writes Altair from Eton. It'll knock and say, Remember me? But it'll look like an obligation, like a lack of choice, like a bad habit. Like apathy, for some. Like sacrifice, or love.

It's 1979, early November, and Blackpool is frigid at this time of year. On the end of the pier, where the open sea eats everything that isn't tied down, Regulus is almost done waiting. Around him, the sea roars, crashing relentlessly against the wood and the steel, soaking his robes and his hair and his skin. His lips taste of salt.

On the faraway beach, a figure peels away from the haze and walks towards him.

"You're late," says Regulus, in lieu of a greeting.

"You got here early," says Altair. He takes a good look around the place where he almost died as a kid. "On the whole," he says, "I think I prefer Brighton."

"Wasn't this your idea?" says Regulus. "At least it's safe. No-one to spy on us but the seagulls."

He looks his brother up and down, as if he's seeing him for the first time. Adulthood suits Altair, he thinks, even if it's still surprising to see him like this. The kind and clever boy, the storyteller has turned into a smooth chameleon, a liar, a trickster. Altair wears his Muggle things - his haircut and coat, his Eton schooling, his First from Cambridge – like armour, or camouflage.

"How's Downing Street doing?" says Regulus.

His brother shrugs. Neither the storm nor the water seem to be touching him. "I'm explaining the fallout from a magical war to people who are not supposed to know there's a war, or magic, or, frankly, a fallout," he says. "What a job! Been telling some pretty big lies."

"You'll be the youngest Minister for Magic in history," says Regulus.

"It'd be worth it just to see Mother's face," says Altair. "How have you been? How's the family?"

It's clear what he's asking. Altair hasn't been in contact with their parents ever since he turned seventeen. He's not interested in Mother's health, or how her devil's snares are doing.

"Bella is pushing for a decision," says Regulus, hardly audible over the roar of the sea. "I don't think I can string her along for much longer."

"And then what?" says Altair. "You'll tell her to go fuck herself and go into hiding?"

Regulus makes a face. He only just got out of Hogwarts, after all.

"Grimmauld Place is safe," he says. "I'm the heir now, it'll protect me and Mother. I can sit it out, if I want to."

Altair gives him a crooked smile. "Sounds like a fate worse than death."

"Tell me about it," says Regulus. "I was thinking of playing along, to be honest. There's some things Bella said that were really odd –"

One thing about his brothers: The speed of their thinking can be quite terrifying. "You're willing to take the Mark because you're curious?" says Altair.

"She says he's immortal!" says Regulus. "I have no intention of putting up with this second-rate Grindelwald for another year, let alone eternity –"

"Oh, Reg."

"You disapprove?"

"Seems to me," says Altair, his voice lighter than his expression, "that there's an X on your back no matter what. Might as well make it count. Speaking of idiotic, irresponsible recklessness, where's Sirius?"

"I don't think he's coming," says Regulus. "I nearly forgot to invite you, too; Cousin Andromeda had to remind me."

"I know," says Altair. "Memory like a sieve, that's our Regulus."

Regulus laughs. "Remind me why we're meeting again? Blackpool is terrible at this time of year."

"Oh, did Andy not tell you? It's your penance, and it's your reward," says Altair. The words tap at something inside Regulus, but he can't place it – again, he's forgotten, how can he forget so many things -

Altair smiles. "Sit down, brother. Cast a warming charm. I brought a picnic; let's have a birthday party for our brother."

He opens his smart leather briefcase. Inside is a tartan picnic blanket, which he spreads over the wet, wooden planks, and the wildest assortment of edible things Regulus has ever seen. It looks like a child has assembled the picnic; scones and fruitcake and pumpkin pasties and pink petit-fours, every-flavour beans that have melted together, soft-boiled eggs and a bun that is sticky with butter and honey, gummi flobberworms and –

"Is that ice cream?" says Regulus.

"Pumpkin flavour," says Altair. "Personally I think it's vile, but I remember you loved it when you were a kid."

There are candles, too, twenty of them. Kneeling on the picnic blanket, Altair arranges them on the fruitcake, making it look like a knobbly, rainbow-coloured hedgehog.

"Think Sirius will like this birthday surprise?" says Altair.

"I told you, I don't think he'll come," says Regulus, and Altair laughs. Regulus laughs, too, even if he's not in on the joke. He settles next to Altair on the blanket, and casts spells to warm them up, to keep the wind and the water away.

"Altair," says Regulus, when he's done. "Altair, I'm thirsty. Did you bring something to drink?"

"Don't you want to wait for Sirius?" says Altair. "He'll be here any minute now."

"Altair, please," says Regulus. "I'm parched."

Altair looks at him with an unreadable expression. At this moment, he seems so very young again, a child. A sad one.

"Regulus," he says. "I know it's not your thing. But could I hug you? Just this once?"

Regulus shrugs. After all these years, he still doesn't get it – but with his brothers, he doesn't mind either way. Altair leans forward and holds him, surprisingly tight, and through it all - sodden robes, wet skin, damp hair – there's a warmth, a solidity, that shakes Regulus to the core. That someone could be so, so alive. So present. Is that the point of hugging? he muses. To know you're alive?

To know your brother is?

"Not long now, Reg," says Altair, but Regulus pays it no mind. He closes his eyes, allows himself to feel this. To learn it from heart. To remember it to the end: Alive.

"Altair, please," he says, when he can't take it anymore. "I'm thirsty; I'm dying with it. Help me."

Altair retreats, and Regulus feels the loss of it – the chill of a gap where there used to be life. His brother bends down to fill a cup with something from a thermos. Slowly. Dragging it out.

"I'm sorry," says Altair. "It's all there is."

Regulus expects water, or tea, but it's neither. Whatever it is, it's phosphorescent, a deep luminous emerald green, and it smells like something from the bottom of a lake - algae, and decay, and something poisonous, like cyanide. Altair presses the cup into Regulus's hands, and Regulus is thirsty, so thirsty, it's this or the water from the unruly sea.

"Drink slowly," says Altair. "Or better, not at all. It'll burn you."

Regulus raises the cup to his lips. As promised, it burns him, and he hesitates.

"Aren't you having any?" he says.

Altair shakes his head.

"If I could take this cup from you –" he starts. "I would. You know that, do you, Regulus? Sirius would, too. So take your time, Regulus, please do that for us - it's the last one. Just one more cup left. One more. Take your time, you're almost there –"

Almost –

Idiot.

Idiot.

Idiot.

Idiot.

Idiot.

Idiot.

Pot.

Kettle.

Black.

Submerged, Regulus thinks of circles. Of periodicity, and of Arithmancy, of oscillations and echoes and full moons. Of things that return.

He returns to the water, and the water to him. Did you know water does not compress under pressure? Air does, and so does earth. Fire burns hot, but it can be smothered. Water does not compromise. It invades him everywhere at once, his mouth, his lungs, his eyes, his ears, every square inch of skin, every cell of his body, smothered and chilled and drowning. On his tongue the taste of metal and death. In his unwilling eyes, green underwater light, a cloud of red from the cut on his arm and they come for it, for him, the only life in the cave, small encapsuled life and soon gone.

Those winter nights are proper dark. Now they reach out with their hands, now they grab his ankles, his wrists, now they pull and pull and pull, they must know which way is down because he lost track of it minutes ago. I can't think of a better place for a son of mine.

And they pull and they pull, down, up, warm light like sunset over Blackpool, waiting for the stars to come out, fire and brimstone. Who cares? You'll be gone.

Rocks scrape across his back and they pull and they pull and they fight over him and he finds it disappointing; he came here to drown, not to be eaten. And he came to drown quickly, not to gasp with his head in and out of the water, not to cough and claw and fight and lose, his vision flickers, on and off, shadows dancing, too many regrets for too short a life. This is your penance, and it's your reward.

His scattered self comes together, sort of, except he's still hallucinating, two cold fingers pressed against his neck and long, wet hair tickling his face, and a voice that says, Nightmare?

Or maybe it says, "He's breathing," and another voice says, in a happy sort of sing-song, "Told you."

Here, this'll cheer you right up. A ghostly shine seeps past his closed eyelids, and he thinks, quietly, No.

Altair did warn him. But Regulus panicked, and now he's a ghost, and he'll have to haunt the cave forever.

Righty-o. He accepts it with some sort of post-mortal calm: Should Voldemort ever come to collect his Horcrux, Regulus won't need a note. He can tell him himself. You know what they say about a man with a big nose?

The same fingers are on his face now, gently pulling his eyelids open. Light wanders over his field of vision, warm light, flickering light.

It's entirely possible the cave is on fire.

This is not quite how he expected his death to go, but he'll take it. His eye falls shut again.

"Reg," says that first voice. Come with me, it's not safe here, it's not safe –

"Ooh, let me, let me! It's been ages," says the second voice, this abomination, this dead thing that couldn't even die properly.

That ghostly shine comes close, close, and then his entire ear freezes up in a cold breeze.

And that voice says, Up, sleepy sloth. Meet me in five. No, that other voice shouts, "WAKEY-WAKEY!"

Regulus can't help it. A jolt goes through him, a quake. He's five years old again, and someone's jumping on his bed. His head lolls to the other side.

"Merlin, what was in that potion?" says the first voice.

Cyanide, thinks Regulus. Arsenic. Aconite. Hemlock. And something nasty…

"Kreacher said it made him feel bad."

"Well, that's very precise. Let me try."

Close again, right next to his ear, but warm this time, warm and breath and life and words. "Reg. Reg? Wake up. Open your eyes. It's over. You're done here, you hear me? You've been brave. So brave. … Well, I don't know exactly what you did here, but it looks very –"

That child laughs. "You called him an idiot!"

"- well, it looks very brave. But now it's time to run. Be scared, Reg, okay? Be scared one more time."

"I'm scared!" shouts the second voice excitedly. "Look, it's very easy!"

"Good boy," says the first voice. "Listen to your oldest brother, Reg. Just survive today. Survive one more day. Tomorrow you can live."

Even if Regulus wanted to engage him, it feels near impossible. His lips move, his eyes flutter, but his limbs are heavy with death and regret, robes weighed down with freezing water and the blood from his arm.

"How's the fire doing?" says the voice.

"They're still scared of it," says the other.

"Not for long."

Then spells are woven all around Regulus, warm spells, dry spells. His robes grow lighter. The spells turn to curses when they find what he's done with his arm, where he's cut it to go through the door. Spells again, and it stops spilling.

"You bloody Slytherin," says the voice. "Don't leave anything to chance, do you? Always a backup plan. Well, fortunately for you, it runs in the bloody family."

Regulus's eyes fall open, more out of accident than anything else. They take long to focus, and when they do –

Of course. Of all his regrets, these two were going to linger all the way to the afterlife.

"Tell him, Altair," says Sirius. He is bleeding, too, but looking blissfully unconcerned. "Tell him how you saved him. Well, first tell him this is a saving. I don't think I'm getting through."

"It was brilliant!" says Altair. "James's mum is so nice and so helpful!"

"I know, right?" says Sirius. "But maybe start at the beginning? When you told him to take you into the cave."

"Oh, that," says Altair. "But that was naughty. I lied!"

Sirius smiles at the edge of Regulus's vision. "He'd have been a Slytherin, you know, Reg. Like Andromeda. Like you. I never thought I'd say this, but," he coughs; despite the inappropriate cheer, he sounds chilled all over, "thank God for Slytherins."

On the other side, the little ghost comes closer again, but this time, Regulus is prepared. The chill doesn't quite go through to his skull.

"It wasn't the last piece," Altair whispers into his ear. "Sirius-like-the-star, he left with the other."

Regulus's lips move. His brain says nothing, but to his great surprise, his mouth says, "What."

"I told you it was the last piece of parchment," says the ghost. "The one you found in the study. But it wasn't!"

"Reg. Reg. Remember the night I told you who he was?" says Sirius. "I kept forgetting his name, so I wrote it on a piece of parchment… I was holding it when you pushed me into the fireplace… Thought I lost it after. Bad night for keeping track of my things." He laughs. "But the Potters never throw a thing away; it ended up in a box with… well, with some terrible photos. Suppose they can throw them out, now that Father's gone."

"Regulus-like-the-star, I told you to take me with you, so I could help you not become a ghost," says Altair, "and that was a big lie, I wouldn't know the first thing about that… Andromeda-like-the-galaxy, she told you to take me, too… I went into the cave with you, and then I ran from one page to the other, and I shouted and shouted for Sirius-like-the-star so I could tell him where you are, but he wasn't there… But James's mum was! So I introduced myself and asked her to call him through the fireplace but -"

"I wasn't home," says Sirius. "I was in Blackpool, on the pier. I waited three days and three nights. Andromeda and I hoped Altair would still be able to go there."

"So James's mum shouted at James through the fireplace," Altair says brightly, "and he knew how to talk to Sirius-like-the-star on the pier –"

"Mirrors," says Sirius.

"- and everyone was shouting and it was all very -" ghosts don't need to breathe, but maybe Altair's still adjusting, "- loud," he finishes.

"Goes to show it takes a whole village to save one idiot brother," says Sirius. "Good thing Voldemort enjoys a slow murder, right? Could have just planted a guillotine on the island. Didn't think of that, eh? Did you say something, Reg?"

Regulus has been moving his lips for a minute now, but no sound gets out that can be heard over their voices and the crackling flames.

Sirius bends down to listen, and Regulus manages to make himself heard. "Neil Armstrong walked on the moon," he whispers.

Sirius laughs. "You've been reading too many Muggle newspapers, brother."

Ah. So he's not quite dead yet. "Kreacher?" he asks.

"That fucking elf," says Sirius. "Pissed off the second the Inferi turned up, didn't he."

Regulus exhales with all the air he has left, which isn't much. "Good elf," he says, so softly that even Sirius has to strain to hear him.

"And speaking of Inferi…"

Sirius springs up, taking a good look around. He obviously doesn't like what he's seeing.

"I think they're getting accustomed to the fire, they're really, really… active," he says. "Splashing about, sort of. Listen, Reg. I brought a broom. You remember flying, do you? I found they can jump quite high from the water. It'll be exactly like Vertical Quidditch. Except with zombies. You don't have to do a thing, you hear me? Just sit up and hold on. How's that sound?"

Frankly, it sounds ridiculous. Even lying down feels like a chore, compared to the cool weightlessness of the lake. But something is shaking Regulus from the inside out, and at first he thinks it's sobs. But no, it's laughter. It doesn't feel like laughter should feel, but it is what is it and he can't help it.

"What's funny?" says Sirius.

There's been nothing but regret in this cave, for Regulus. So maybe that's what allows him to speak: The greatest regret of all. The knowledge that he must die, today, when he least wants to – that he will never know whether he did make up for his sins, after all –

He motions Sirius closer so at least he won't have to speak up. "You think I didn't think of this?" he says. "You think it never crossed my mind to fly? This is the man who cursed a teacher's post. You think he wouldn't curse a door?"

The long speech tires him, and he's coughing, and it tastes of blood and lake water and cyanide.

Sirius is still for a long, long time. Then he says, "We paid for our passage."

Regulus feels more exhausted than he ever has in his life, gravity pulling at his every fibre, and he whispers, "It's a one-way ticket, moron."

"Fucking Voldemort," says Sirius, who has never met the man and therefore has no idea how accurate his assessment is. "How much for the return, then?"

"How much do you think?" says Regulus.

Above him, Sirius finally, finally seems to appreciate the brilliance of the Dark Lord. "A death," he says. "Oh, that is so like him."

Regulus shakes his head, which turns out to be a bad idea, in hindsight. His skull hurts all over from it. "Something better," he says. "Or worse. It marks a soul for departure. One soul. Just one. It's an old, slow curse… it'll take a day or two, but -"

"Brilliant," says Sirius. "Loads I can do in two days. Break's over, nerd. We're playing Quidditch." He grabs Regulus by the arms, manhandles him into an upright position so quickly he's seeing stars. But Regulus doesn't fall. Not that he has any say in it; Sirius keeps him propped upright, carrying the vast majority of his weight.

At first, Sirius's obnoxious high spirits just make him dizzy. Then, they makes him angrier than he has believed possible. "Sirius Black," he croaks. "Leave me alone, there's no point -"

"Like you're an expert on what the point is," says Sirius. "Idiot."

"It marks a soul for departure," says Regulus, feeling like a broken record. "And it's not going to be you, you fucking Gryffindor."

"Well, it's not going to be you, you fucking Slytherin," snaps Sirius. "Not if I have any say in it."

"You don't, idiot," shouts Regulus. He's not quite sure where the air comes from, or the energy, except he'll always have the energy to call his brother an idiot – especially now, when Sirius is still essentially holding him up, closer than he's been in years. It's just asking for a good shouting match.

"If you want a go with Voldemort's toys," says Regulus, "you'll have to play by his rules. It marks a soul on the exit, and no, you can't choose which. First one in is the first to go. It's written on the door, didn't you look?"

"Well, it was fucking dark!" shouts Sirius, before becoming very, very still. He looks at Regulus, and Regulus looks back.

"Yeah, and the runes were invisible," says Regulus. "I know."

"But that's you," says Sirius, in the voice of someone who is point-blank refusing to believe. "First one in, that's you."

Regulus steps back, a tiny, unstable step, so he can stand on his own, bear his own weight. Then, slowly, to not disturb the careful equilibrium of his still reeling body, he nods.

"No," says Sirius. "No, that's impossible. You got it wrong."

"Got an Outstanding in my Ancient Runes N.E.W.T.," says Regulus. He tries a grin. "And people say it's an obsolete class."

Sirius doesn't laugh at his feeble joke. For once in his life, he seems thoroughly at a loss. The silence between them is cold, and it's terrible.

There isn't only regret in him, Regulus finds. There's softness now, too. Softness and heaviness and something that's light and fleeting. Too many things at once, whirling and rising up, up. He wishes he could build a bridge across this maelstrom, because words don't seem enough.

Still. "Sirius," he says. "Thank you for trying."

"I'm not trying," says Sirius, who seems to have found his voice. "I'm just not finished doing it yet."

"Do what, Sirius?" Regulus says, as gently as he can.

Sirius opens his mouth to speak, to offer up a million possibilities – like he can carve a new door into Voldemort's cave, or find a countercurse in two days' time – but before he can speak, a third voice pipes up. "Can I tell you a story?"

Sirius's eyes do not leave Regulus's. "Not now, Altair," he says quietly. "This is important."

"It's a very important story," insists the ghost.

An echo whispers in Regulus's mind: I do believe in fate... She fights back, and she fights dirty. So we fight dirtier.

Oh, god, thinks Regulus.

They look at him, then. The ghost is sitting on a rock, legs dangling, undisturbed by cold and fire and the dead things from the lake. After all these years, he's still only just drowned, hair like seaweed and luminous water dripping from ever fibre. The beginning, and, alas, the end.

"Go on, then," says Regulus.

"Do you remember Blackpool? Before, I mean," says Altair, and they nod. At least, Sirius does. "Most years, we'd all go to Fleetwood, to visit the Haunted House –"

Regulus shakes his head. Now that Altair is speaking, the dizziness is back, the cold, the impending death. His thoughts are circling in on themselves, and the last thing he feels able to do is holding on to impossible things. "I'm sorry," he says. "It's still not –"

But Sirius nods again. "The dungeons?"

Altair beams at them. "The dungeons were where the sad ghosts were. The ones without fingers and toes. They would hardly come out at all."

"Wasn't it kind of dark in there?" says Sirius.

"So, so dark," says Altair. "Sirius-like-the-star, you wanted to jump down the trapdoor, but I said no, I said – remind me – what did I say?"

"I'm the oldest, I go first," says Sirius. The simple memory makes him smile – until Altair nods, too.

"Yes," says the ghost. "I go first."

Despite all, Regulus is the first to realise. "No," he says. "No, that's impossible. You weren't even there when I stepped through the archway."

"I told you," says Altair, "when I first found you on the pier. Didn't you listen? I'm water. I'm a light on the waves. Think you're faster than light? Think I'd just let you wander into a scary old cave?"

It may be an indicator for the sort of day Sirius had, but when he finally catches up, he, too, says, "No." He says, "You're a child."

"I'm a soul," says the ghost, but he doesn't seem unhappy. In fact, today he's been happier than Regulus has ever seen him.

"Regulus-like-the-star asked me why I'm still here," adds the ghost. "Why I never moved on. Think this might be why? Think we can trick the door? I don't suppose the curse can kill me; I'm already dead!"

"So are the things in the water, and look at them," says Sirius.

"They're the opposite of me," the ghost states, thoroughly unconcerned with the Inferi creeping up on them.

"Exactly," says Sirius. "How do you think they came about? Think there might be something in here that eats souls?"

That's not how Inferi are made – Sirius is probably thinking of Dementors - and the prickly smart-arse inside Regulus wants to point it out, but no. Bigger things at stake. Besides, Voldemort is one inventive bastard. Would he truly rule it out?

Sirius takes a deep breath, then another, like he's inwardly counting to ten. Must be a new trick he picked up from his friends.

"Regulus," says Sirius, when he's done counting. "You're the resident expert for Voldemort's many fucked up perversities. Tell Altair this trick won't work. Tell him we'll find another solution."

What other solution? thinks Regulus. It's not like I haven't looked. He wishes his mind weren't quite so thoroughly addled. He wishes he could give all this – the tragedy of it, the heaviness, the sacrifice, bloody fate – his full attention. But right now, he's reading his own thoughts like pages in someone else's diary.

"The Dark Lord didn't prepare for a house-elf," he says, and it's the truth . "I'm willing to bet he didn't prepare for a ghost."

Regulus looks at the child, and thinks, Sweet Dreams, Dear Child. He thinks, It's not sweet, and it's not a dream. He thinks, Fate. It'll look like sacrifice, or love.

He thinks, the Inferi are really coming quite close now.

"Willing to bet!" says Sirius. "Well, I'm not! I fought so hard to remember him! I only just got him back! There has got be another way -"

The ghost jumps up from his rock and he advances, luminous and so terrible that Sirius side-steps to hold on to Regulus, shield him or be shielded by him, and good luck with either.

"Sirius-like-the-star!" shouts the ghost, as the Inferi creep up all around him. "You never got me back! I am dead! I am gone forever! Our mother killed me when I was seven! And there's nothing you or I or anyone can do to change it!"

Sirius is silent for a long, long time. Then he says, "Yes, I know." His face is oddly blank, but the way he squeezes Regulus's shoulders tells him all about how well Sirius is taking this.

"I've had ages to think about it, and I'm glad you remember me now," says Altair. "But remembering is all anyone ever gets. I'm sorry."

"I know," says Sirius again. "I'm sorry, too."

"And you," says the ghost. "You're so alive. Regulus-like-the star, he's so alive. You're not good without him. And he – have you seen him? He's pretty dumb without you, too."

"Tell me about it," says Sirius. He even tries a smile. Only his fingers dig into Regulus's shoulder, as if he's never going to let go again.

"So that's how we're doing it" says the ghost. "Hop on the broom, I'll lead the way."

"And what if – what if you're wrong -" says Sirius.

"If the curse gets me? I'll move on," says Altair, and with that, he's back to normal: Timid. Scared. Childlike. "Would that be so bad?"

Sirius opens his mouth to answer, oblivious to everything except the ghost. Regulus pulls back, moving as if through molasses, but somehow he gathers enough momentum to crash into Sirius, push him away from a wandering dead hand protruding from the water's edge.

The Inferi are definitely getting used to the fire.

"I suggest we leave," he says.

"Regulus-like the star is right," says the ghost. "We need to hurry, or they'll eat you!"

Sirius just nods, unable to speak. He helps Regulus onto the broom, holds him tight as if Regulus were a lifeless puppet about to drop sideways, which, to be fair, is not too far from the truth. But Sirius's flying is impeccable, and they reach the archway in less than a minute, the ghost lighting the way.

"Altair-like-the-star," says Regulus.

"Yes?"

Nothing, thinks Regulus. Except someone should probably say something, because this is where the curse will mark one of them: On the exit. Now.

The Inferi are coming after them in staggering waves, so it'll have to be short. And Sirius doesn't do goodbyes, so it'll have to be Regulus.

"Nothing," says Regulus. "It's just – like-the-star. I've always liked that, you know."

Leaning against a wall covered in invisible runes, he watches Sirius open the door with an offering of blood, stony-faced and pale and resigned.

"I've watched the stars," says Altair. "For a hundred million years, I've watched them, and you know what?" He whispers conspiratorially, "The stars are like us."

The archway opens, and Sirius smiles, a brief, grim smile before he waves them all through.

They crash the broom on an unnamed beach far, far away from Blackpool, too exhausted to go on. A triangle: Stars above them, darkness behind them, and a shine on the water, a light on the waves.

An ending, a beginning, a miracle.

The end.

Note 2: I tried. I tried to stick to canon (that'd be the first and second ending I wrote, out of like seven). But I couldn't do it in the end. They already went through hell in this story, and enough is enough. If AU's not your thing, feel free to consider this chapter an add-on.

Please, if you got this far and enjoyed the story (hell, even if you didn't – though in that case, I admire your stamina), consider leaving a comment and tell me what you think – the good and the bad :)