Chapter Text
James Potter was exhausted.
His head pounded, his clothes were wrinkled, and his arms ached from holding a feverish, screaming baby for hours on end.
Harry had been inconsolable all night, his tiny body burning up against James’s chest, his face red and blotchy from crying. Stray sparks of magic flared around him, flickering embers of energy he couldn’t yet control, a telltale sign of Mageflame Fever.
A common sickness among young witches and wizards, they’d said at St. Mungo’s. Nothing dangerous. Completely normal.
“Just keep him hydrated,” the Healer had advised, all calm and clinical while James was practically falling apart. “Give him this fever reducer once his magic settles, and he should be fine by morning.”
Morning had come. Harry was not fine.
The potion? Spat out.
Cooling charms? Screamed through.
Holding him? Not enough.
Putting him down? Absolutely out of the question!
He was miserable, and nothing James did helped.
James had called Sirius and Remus out of sheer desperation, hoping they might offer some kind of distraction. Sirius had been the first to try.
“Oh, kiddo,” he’d said, trying to lift Harry up from James’ arms. “Uncle Padfoot’s here, yeah? Let’s have some fun.”
Harry had sniffled, eyes glossy and big, and for one fleeting second, James had thought, maybe this will work.
Then Harry shrieked, moving closer to his dad, and shoved his tiny hands against Sirius’ face.
With a loud BANG, Sirius was flung back into the couch, hair now an alarming shade of lime green.
Remus had howled with laughter. Sirius, sitting up in a daze, had scowled at James. “You owe me for this.”
Remus had been next.
“Alright, little cub,” he murmured, taking Harry gently and settling him against his chest. “I know you don’t feel well, but how about a story?”
Harry stilled for a moment, blinking tiredly up at Remus.
James leaned forward, barely breathing. Please work, please work, please...
Harry’s face crumpled, and he threw a full-blown tantrum.
Flailing, crying, his little hands clawing at Remus’ shirt, trying to get away.
James had groaned. Sirius had sighed.
And through the sobs, one desperate, pitiful word had broken through.
“Weggie.”
James had frozen.
“Reggie?” he echoed.
Harry had hiccuped, nodding miserably against Remus’s shoulder.
“Weggie,” he whimpered, curling his fists into the fabric. “Weggie.”
Sirius had shot James a bewildered look. “Are you bloody serious?”
No, you are. James immediately thought but had been too exhausted to respond. He’d just gone straight to the floo, called Regulus’s shop, and practically begged him to go over to his house.
And now, mere minutes later, Regulus was stepping out of the fireplace, his tailored black robes untouched by soot, a sleek case of potions in one hand.
The second he appeared, Harry wailed and reached for him, arms outstretched.
Regulus didn’t hesitate. Didn’t even blink. He strode forward, took Harry from James’s arms, and held him close.
And just like that... silence.
The sobs stopped. The flailing stopped. The sparks of uncontrolled magic stopped.
James, Sirius, and Remus could only stare.
Regulus sighed, pressing a cool hand to Harry’s flushed cheek. “You’re burning up, little lion,” he murmured. “Let’s fix that, shall we?”
He carried Harry to the couch and settled down, reaching into his potion case with practiced ease. He pulled out a small vial filled with a soft, glowing blue liquid.
James watched, still catching up to the fact that his son, who had been screaming for hours, was now tucked into Regulus’ chest, sniffling softly instead of howling.
“What’s in that?” James asked.
Regulus uncorked the vial, tapping the rim against his wrist. “A specialized fever reducer. Stronger than the St. Mungo’s version, but gentle enough for children. Contains a dilution of moonstone essence to stabilize his magic, asphodel for the fever, and honeyroot for better taste.”
Harry wriggled slightly, eyes drooping, and whined. “No potion.”
Regulus hummed, amused. “Stubborn thing, aren’t you?”
He adjusted his grip, cradling Harry with one arm while bringing the vial to his lips. “Small sips, little lion,” he coaxed. “It’ll help.”
And just like that, Harry drank.
James felt his jaw drop.
Sirius threw up his hands. “Oh, come on!”
The potion took effect almost immediately. Harry’s fevered skin cooled, the restless sparks of magic dimmed, and his tiny body relaxed against Regulus’s chest.
Regulus carded his fingers through Harry’s messy curls, a motion so gentle, so natural, that James almost forgot to breathe.
Harry, barely awake, sighed. “P’eetty.”
Regulus blinked. “What?”
James, still in a daze, translated. “He said you’re pretty.”
Regulus rolled his eyes. “Clearly, he has a fever.”
James, despite everything, laughed. “Nah, he’s just got good taste.”
Regulus stilled for half a second, a flicker of something unreadable in his expression, before he shook his head and stood.
“Can I use your kitchen? I’ll make him some soup,” he said, heading toward the kitchen without waiting for a response. “Something light so his stomach doesn’t reject the potion.”
James, Sirius, and Remus watched in stunned silence as he disappeared into the next room, Harry still securely in his arms.
Sirius looked deeply offended. “So, just to be clear... all he needed was Regulus? What are we even here for?”
James exhaled slowly, raking a hand through his already-messy hair.
“Yeah,” he admitted. “Your brother has a magic touch apparently.”
Later, when Harry was clean, full, and sleeping peacefully, James found Regulus still in the living room, flipping absently through a book as if he hadn’t just saved the entire night.
James sat beside him with a quiet sigh. “I don’t think I’ve ever seen anything like that before.”
Regulus didn’t look up. “Like what?”
James studied him. “Like you being the only thing my son wants when he’s sick.”
Regulus was quiet for a moment. “It’s not my fault you’re incompetent.”
James huffed a laugh, shaking his head. “And yet, somehow, I’m still grateful.”
That made Regulus pause. He glanced at James, something unreadable in his dark eyes.
James swallowed, suddenly feeling the weight of everything. The exhaustion, the panic, the relief.
“Really,” he murmured. “Thank you. For coming.”
Regulus held his gaze for a long moment, then looked away.
“I’ll always come if he needs me,” he said softly.
Something in James’ chest tightened.
Before he could think too hard about it, he reached over and gently squeezed Regulus’s hand.
“Yeah,” he murmured. “I know.”
And for the first time all night, James finally let himself breathe.