Fiendfyre
February 19th, 1980
Regulus
Hands claw at his skin, dragging him down into the lake where the darkness surrounds him from all sides. He can no longer see the feint glowing light from the basin, nor can he feel the heat from the fire he tried to cast to ward the Inferi off as a last resort. It’s painfully cold, so much so that he wonders if he’ll die of hypothermia before he even drowns, even as the water is rapidly filling his lungs with every attempt he makes to scream out for his big brother.
Sirius won’t come. He knows that. He knows that even if Sirius knew where he was, that he was about to die, he wouldn’t come. But the fear that grips Regulus even tighter than the dozen hands gouging into his skin make him revert to that scared little boy he used to be. The one that would crawl into Sirius’ bed at night after waking from a nightmare, or ask Sirius to check for monsters in his closet.
“Sirius!” Regulus cries out, jolting awake in a panic. Scrambling out of the sheets, he falls to the floor of his bedroom with a hard thud, panting hard, gasping for breaths of air. In his frightened state, breathing doesn’t come easy to him, and he’s probably crying, but he’s too disoriented to tell.
It takes several long minutes to calm down and become aware of where and when he is. Still laying in an uncomfortable heap on his bedroom floor, he stands up slowly, gripping the post of his bed for reassurance. In the water, his own hands had been unable to find purchase on anything other than the Inferi. The dry wood under his fingers is grounding, but there’s a chill in the air that won’t let him forget.
Regulus makes his way embarrassingly quickly down to the library, both relieved and confused to find the fireplace already lit, then he sees Remus sitting awake in a chair beside it, a heavy book open in his lap. He watches Regulus warily as he goes to drag the empty chair across from him closer to the fire, and curls up in it in an improper position that his mother would surely scorn at. If the other man had heard any of what had just occurred, Regulus’ bedroom being just above the library, he says nothing about it, which Regulus is grateful for.
“That’s not research,” Regulus says, attempting to distract himself, horrified to find that his voice is hoarse. He must’ve been screaming in his sleep, calling out for Sirius repeatedly.
Remus ignores it, nodding down to the book in his lap. A thick fantasy book that Regulus thinks is muggle. He’s sure there wouldn’t have been anything like that in this house. “Needed something to refresh my mind. We’ve been frying our brains the last weeks, and nothing good has come of it so far.”
“Fair enough. Where on earth did you find that book in this house. My father never kept novels like that in here.”
Remus hesitates, before looking away from Regulus. “It was upstairs.”
Regulus takes a moment to realize that he must mean he found it in his brother’s room. He’s surprised to think that Sirius would be interested enough in recreational reading to own any books, but then again, anything that would piss off their mother could probably be found in the presently unoccupied bedroom that once belonged to Sirius. He might’ve been irritated that Remus had gone looking around it, were he not mortified at the implication behind Remus hesitance to speak Sirius’ name, that he had indeed overheard Regulus crying out for his brother in the midst of his nightmares. He wonders how often he has.
Making a mental note to cast silencing charms before sleeping from now on, Regulus changed the subject. It’s the chill that he still feels to the very bones under his skin, the fireplace doing a dismal job at warming him up, that makes him decide on it.
“I’m going to learn Fiendfyre. It’s the best bet we have so far, and I’d rather not continue wasting time.” Every moment they don’t act is a moment someone they care about could die. Or in Regulus case alone, that someone he cares about could end up in Azkaban for life.
A pang in his chest hits him as he thinks of Barty and Evan for the first time in weeks. He’s been avoiding thinking about the subject. He hopes they’re safe, though knowing the two of them, the more danger they’re in, the more fun they’re having. Regulus gets it, the thrill from the adrenaline rush. He doesn’t think he could enjoy the feeling anymore though, not after the cave.
“You know,” Remus begins, closing his book and placing it down on the small end table beside him. He pauses for a moment, as if choosing his next words carefully.
“I suggest you mind what’s about to come out of your mouth, Lupin, or I’ll curse you to hell and back,” Regulus warns, not in the slightest bit joking, which Remus must know.
But he continues anyway. “He still cares about you too, more than anything.”
The words are like a slap to the face and it’s the last thing Regulus was expecting on the topic of Sirius. It stuns him so much to hear that he’s silent for a long moment. His expression must be pitiful, because Remus gives him a small, reassuring smile. Remus was safe, so narrowly in the clear for speaking about it, but then, just as every foolish Gryffindor Regulus knows, he has to go and continue opening his mouth. “I know you’re relationship is complicated, but when he’d heard about your death he-”
“What the fuck would you know about complicated sibling relationships, Lupin?” Regulus snaps harshly. “Not a thing. You’re an only child, so you should mind your own gods-damned business.”
Remus appears genuinely pained by this, the look that flashes across his face being ironically reminiscent to that of a kicked puppy. “I would know a great deal more than you think, Reg. Just…” he seems to think better of whatever he meant to say next, and merely gets up and leaves the room.
There are some moments that Regulus feels this weight weighing down on him, crushing until he’s folding in on himself and wishing that the weight was real enough to kill him. It gets hard to breathe, his whole body begins to feel clammy, and his heart starts racing. He doesn’t know what causes it, he’s had the moments since he was a child, the first time it ever happened was the night before Sirius left for Hogwarts the first time.
He’d run into his brother’s room, sure he was dying from the way his throat was closing up and his body was trembling. Sirius had merely told him he’d be fine in a few minutes, that he got those bad moments too sometimes. He’d held Regulus through it, whispering soothing things to him.
This is one of those moments, that weight pushing and pushing and pushing down on him until all he feels is the lightness of his arms as they shake and the impending nausea that inevitably comes with. He tries to ignore it, taking deep breaths and thinking of comforting things like Sirius had taught him that first night. It doesn’t help, just like it never did. The only time he’s ever felt relief during a bad moment was that first one, wrapped tight in Sirius’ arms while his big brother massaged his hair and hummed lullabies to him.
Regulus is itching to take his pain and anger out on something, unable to wait for the bad moment to pass. He stands in the old wine cellar, emptied out now, though his father would probably have had a stroke if he found out that Regulus threw out most of the priceless bottles, keeping only a few that he’s moved to the kitchen now. Focusing on the chair he brought down from the drawing room, a random piece of furniture he selected. Raising his wand and willing his hand to steady, he aims for the chair, the only flammable object within the four stone walls, aside from himself, and he casts the spell.
It doesn’t work. Nothing happens and he feels immensely disappointed. He’s never had a problem before with getting a spell to work. Maybe he doesn’t always get it perfect on the first try, but he usually gets it at least halfway accurate.
Regulus closes his eyes and takes a deep breath, casting again, slower and with as much more deliberation as he can muster this time. A pitiful flame shoots from the end of his wand, but it’s all that’s needed to render the chair to ash in a matter of seconds, the black flame eating at the wood and upholstery like it’s starving. It’s unnerving to think that fire is truly alive, in a sense. Maybe that’s the idea behind Fiendfyre, to create something animate, with free will.
Too free. The flames remain after the chair is nothing but a burn mark on the stone floor, and when Regulus tries to cancel the spell, they only flare up, as if angry. He takes a step back as they grow to engulf nearly half the room in a split second, his palms turning sweaty. The heat is unbearable, and yet there’s a chill that runs down his spine. He wonders briefly if this is how he’ll die, after everything, and for nothing. He hopes Remus won’t try to cast Fiendfyre and get himself killed as well.
There’s a shout of alarm from behind him, and Remus is pushing him aside, knocking him to the floor, and in the moment that his attention is broken, Remus somehow cancels the spell, vanishing the flames with a wave of his hand, though Regulus doesn’t notice his wand, or catch the incantation he must say.
The older man turns to stare at Regulus, still on the floor, panting hard. “You bloody idiot,” is all he says, sounding winded. The relief and adrenaline flooding through Regulus must make him a bit delirious, because he just starts laughing, and Remus cracks a grin himself.
“Well,” Regulus says. “That’s a start.”
“It should be a finish, as well.”
“No. If I can cast it and you can cancel it, that’s good enough for me.”
And Remus sighs in resignation.