Disclaimer: I own nothing, except the plot.
It's twenty minutes past midnight when John Watson is woken up by his boyfriend's drawl in his ear. "Wouldn't it be wonderful if we could live forever?"
Instead of the usual inquiry he would give, John lets out a sigh before pressing his face into his pillow. "You've gone in the Restricted Section again, haven't you?"
He feels the covers shift, and, soon, cold toes jab at his bare ankles. "So what if I have? I'm just researching. Hardly anything wrong with that."
John tries to scoot away, pulling the blankets back his way. "It's past curfew, Sherlock. You're lucky you weren't caught."
"Oh, John, it's amazing how you think a few prefects can incapacitate me."
"Forgot about the coats of armor... ghosts," he mumbles, shutting his eyes. Sherlock shifts behind him again and slips his arms around John's waist. Rolling his shoulders and pressing into him, John glances over. "Four times now?"
Sherlock sighs and shuts his eyes, pulling John in close. "What?"
"Four nights you've stayed in here. Come to think of it, you're lucky you've never been caught here either." Sherlock's lips curl in a smile. John shakes his head and sighs as he settles back down. "One day you won't be so lucky."
"Tonight's not that day. Now, shut up, or I'll hex you."
John smiles and nudges Sherlock with his elbow. He receives another jab in the ankles.
When John wakes up the next morning, he isn't surprised to find the other side of his four-poster bed empty. The Ravenclaw never stays for the whole night, to John's disappointment, but he figures Sherlock has to sneak back into his own tower before anyone rises.
As he slips out of bed and joins the other Gryffindors in their morning routines, he remembers the conversation he and Sherlock had hours ago. Something about living forever and researching in the Restricted Section. Now, he can barely recall anything of importance, or if they even delved into the topic any further, so he makes a note to pester Sherlock about it later.
Once downstairs, he runs into Harry and talks about their upcoming exams.
An apple is placed in the middle of John's plate. He blinks and stares at it, swallowing what's in his mouth before looking up and seeing Sherlock. He furrows his brow and points at the fruit with his fork. "What's this?"
Sherlock shoots him a look before placing a book on the table top. "An apple." He slides his index finger along the top of the volume and opens it to a spot in the middle.
John shakes his head and pokes at it. "What for?"
"Thought you'd want it." When John starts to laugh, Sherlock narrows his eyes and reaches out, grabbing the red fruit. He roughly bites into it and stares at his book. "Fine then," he says, spit hitting John's cheek. "Enjoy your eggs."
The blonde raises a hand and wipes off his face. "No need to go all"—he looks him over—"Grindylow."
Without removing his eyes from the page, Sherlock smirks. "What are you talking about?"
John smiles and looks down, stabbing his egg. "Nothing apparently." He bites into a piece of toast and glances around the Great Hall. He watches a few first-year Hufflepuffs gather at the end of their table, exchanging notes, their expressions frantic. Two Slytherins, a seventh-year boy with brown Basset Hound eyes and a sixth-year girl with bright-red lipstick, walk behind the group and laugh, seemingly at an unspoken joke. John purses his lips and returns his gaze to Sherlock, who had still not looked up from his book. He studies him for a moment or two before shifting his food around on his plate. "What were you doing last night?"
Sherlock turns a page, lifting his head. "I told you. Researching."
"Yeah, but researching what?"
"Did I not tell you?"
"No. You said something vague and poked your cold toes into my ankles." Sherlock grins and lowers his eyes. John shakes his head and sets his silverware on the plate, pushing it away. "If it's what I'm thinking, Sherlock, then—"
"—then what, John?" He looks up again, narrowing his eyes. "Research is harmless, regardless of the subject matter. I don't see what the big deal is."
John shakes his head. "It is a big deal, Sherlock, but, of course, you don't see it." He shrugs and picks at a spot on his sleeve. The other huffs and bows his head, looming over his book. John sighs and leans in. "I know what happens when you research. You get ideas, and you want to experiment." Sherlock turns and moves his book off to the side, keeping his eyes glued to the page. "Don't act like that. You know exactly what I'm talking about." He slams the book closed and looks up, glaring at John, who holds up his hands. "If you don't want to hear it, then walk away." Sherlock gives one last, long look at John before standing up and pulling his book to his chest. He stalked off, leaving the blonde, who shakes his head again and smiles. "See you in Charms."
John's cedar wand seems to vibrate against his fingertips as he brandishes it towards Sherlock, an incantation screaming in his head. Nothing appears out of the tip of the wood, which makes him furrow his brow. He waves and jabs his wand out again.
Sherlock raises an eyebrow and watches him. "You look so determined, but, please, do stop." He laughs.
Sighing, John lowers his wand and looks at it in defeat. "I'm rubbish at nonverbal spells."
"Might as well get used to it," the other says, gracefully waving his wand. A bubble forms around his head, and he pulls a huge grin. He looks at John and waves a hand. "Tada."
John narrows his eyes and straightens up. "Yeah, well, your voice sounds silly in there." He starts to tap his cheek with his wand and furrows his brow, focusing on the desired result.
"What my voice sounds like doesn't matter, John. The only thing that matters is that the outcome is effective and works." He waves his wand, and the charm disappears into the air. He turns to John, who is still staring at a spot on the desk. "Are you concentrating?" he asks in a low voice.
The blonde shoots him a glare. "Of course I am. What else would I be doing?"
Sherlock narrows his eyes. "I was just trying to—"
"—hush. You're ruining my… concentration." He looks to the front of the room and spies the teacher making his way over to them. His heart quickens, and he manages to mutter the right words to create the protective bubble around his head as soon as the small teacher appears in front of him.
"Nice work, Mr. Watson, but I would like to see less lip-moving."
He elbows Sherlock when he lets out a dry laugh.
After class, Sherlock grabs John's arm and starts to pull him towards the library. "Let me show you this book I'm reading."
John frowns and tries to shake his arm out. "Not now, Sherlock, I have Muggle Studies next, and it's all the way on the fifth floor, and the staircases have been acting moody lately."
Scoffing, Sherlock releases John's arm. "Dull. Just skip it."
"I can't just skip a class, Sherlock." He meets the taller's gaze and sighs. "Well, yeah, I can, but I really enj—"
"—oh, please do not say that you enjoy that insufferable subject."
"It's useful information."
"Only if you're going to live in the Muggle world, John. Who could possibly—oh." He slowly straightens up and examines the shorter, eyes widening as if John is a children's picture book and with a single page turn, a random, unexpected page of elaborate words greets him. He narrows his eyes and takes a step forward. "Oh," he repeats.
John shakes his head and holds out a hand, lightly touching Sherlock's chest. "No, don't." He steps back and scratches his head. "We'll talk about it later." He waits for a reply, but receives none, only an icy stare from Sherlock. He purses his lips and looks at the wall. "Show me what you've been reading, researching, whatever, too. Later." He nods and turns back to him. "Even though I have a feeling about what it might be."
Sherlock carefully studies him before turning. "You're going to be late." And with a flourish of his robes, he moves into the library. John keeps an eye on him until he turns the corner and disappears. He clears his throat and fixes his tie as he heads towards the staircases.
It's dinnertime when John is able to talk to Sherlock again. After a particularly grueling Herbology lesson, John sits down at the Gryffindor table, staring at the golden plate in front of him. Food materializes on the surface, and he gives a small smile as he picks up his silverware. He looks over and spies Harry on the other end, getting awfully close to a seventh-year Hufflepuff girl. Deciding against playing the obnoxious brother card, John starts to eat.
His short moment of peace is brought to an end by long fingers running through his hair. John jumps and bangs his knee against the table. Holding back a curse, he turns his head and sees Sherlock standing behind him. The dark-haired has his fingers up to his face, examining them. He glances at John and wrinkles his nose. "Cobweb," he says, holding out his hand.
John shakes his head. "I don't want it back." He turns back to his food, stabbing a piece of meat with his fork. Sherlock quietly slips beside him and looks down at the empty plate in front of him. He pushes it away and turns to John, stretching out a hand and wiping the cobweb against his robes. "Thanks, Sherlock," he says, nodding and looking at him. "I needed that."
Sherlock hums and scoots close, extending his other hand and taking a roll from John's plate. He starts to tear it into tiny pieces before eating them. "Don't mention it," he quietly replies, giving John a small smile. He nudges the blonde. Returning the gesture, John ducks his head down and hides his smile as he digs into his baked potato. Sherlock laughs and shakes his head. "John, you are a marvel." He finishes half of the roll before setting it back on the plate, wiping his hands on a napkin. "Come to my dormitory tonight."
John pauses and blinks at the wall. He glances at Sherlock, meeting a determined stare. "Okay," he says, nodding. He looks back down at his plate and clears his throat. "Alright."
"Excellent. I hope you're good at riddles."
John frowns and turns his head, just in time for Sherlock to press a kiss to his forehead. He sighs and moves away. "Why can't you come up to my dormitory? It's easier."
"Oh, John, like you said last night, it's only a matter of time before I got caught. You, on the other hand, have a clean slate." Sherlock swipes the remainder of the roll and tosses it into the air. Catching it, he flashes John a smile. "Good luck." He stands up, sneaking in a squeeze to John's shoulder before leaving.
The clock chimes eleven when John slips out of Gryffindor Tower. He bites his lip as he creeps through the seventh floor, slipping past prefects when needed. He catches himself peeking into the suits of armor whenever he gets too close to one, but manages to quench that fear after passing the sixth stationary armor.
He makes his way to the fifth floor, up the tight spiral staircase, and, finally, stands in front of the door without a knob or a keyhole. John stares at the bronze eagle knocker, narrowing his eyes at it. "Alright," he breathes out, nodding. He reaches out and lightly knocks on the door.
Soon, the eagle's beak opens, and a musical voice emerges. "What is the antidote to every poison?"
John stands there, frozen. He stares at the door and shuts his eyes. "Goddamn it," he breathes out, shaking his head. He rakes his mind through each Potion lesson he had that dealt with antidotes. He remembers the Bezoar, a stone taken from a goat's stomach that could save you from most poisons. He's about to spout it out, and then realizes the riddle called for every poison, not most of them. John squeezes his eyes shut and imagines punching Sherlock in the face.
He remembers learning about laws and principles, and remembers flipping through Advanced Potion Making. His eyes widen, and he straightens up. Golpalott's Third Law!
"There is no one antidote for every poison."
John's face falls. He turns behind him and immediately narrows his eyes. Sherlock's standing not too far behind him, hands behind his back, as if he's been there the whole time. "I was going to answer that," he says. Sherlock shrugs and walks over to him, the knocker supplying a "correct" before opening the door. He starts inside the common room, a light hum in his throat. John follows behind him, shoulders squared. "If you were waiting out there this whole time, why couldn't you come to my dormitory?"
"I wanted to see how you done." He looks over his shoulder and stops in the middle of the common room. "How were you going to answer?"
"Golpalott's Third Law."
Sherlock smiles, studying John. He turns on his heel and starts towards the statue of Rowena Ravenclaw, the entrance to the dormitories. "Come on, then."
John, however, digs his heels into the floor and shakes his head. "No, Sherlock." He sighs and shuts his eyes, raising his hands to rub his face. The other says nothing, which makes John let out a frustrated noise before dropping his hands. "You should have come to my dormitory. You're better at sneaking and creeping around. I almost got caught."
"I'm inclined to disagree, though I don't know what you endured coming up here," Sherlock remarks, tilting his head to the side as he studies John.
"That's right. You don't."
Sherlock walks over to the other and stands in front of him. Watching John with a careful eye, he raises a brow. "I assumed you wouldn't care to do this. You wanted to come."
"Well, of course, I wanted to, you big—"
"—then what's the problem?"
Feeling a breeze of cool air, John crosses his arms over his chest. He shrugs and shakes his head again. Sherlock stays quiet and studies his face. Soon, he reaches out a hand and presses his fingertips to John's cheek, applying slight pressure. "Stubborn," he says.
"Idiot," John snips back, smiling. He turns away and points at the doorway beside the statue of the Ravenclaw founder. "Dormitory through there?" He walks over, glancing behind him. "Come on, then. Show me this research. That's what you really want, right?"
Sherlock rolls his eyes and silently follows behind John, not wanting to give him the satisfaction of a reply.
Minutes later, the pair is back in the common room, sitting down on one of the couches next to a few bookshelves. As Sherlock spreads his notes onto his lap, John studies the domed ceiling. He smiles and leans against the back of the couch. "That's beautiful."
"What?"
"The stars." John gestures to the ceiling. He laughs and shakes his head. "It's just neat." Sherlock hums as he brings a book towards his chest, readjusting his position on the couch. He opens it and starts to flip through the pages. John cranes his neck and glances at the cover of the book. "Secrets of the Darkest Art?" He frowns and looks over. "Was this in the Restricted Section?"
"Yes."
"How were you allowed to take it?"
Sherlock only smiles. He runs his fingers through his hair, pushing the wild curls back. "Here." He points at a passage and tilts the book to show John.
John scoots close and begins to read. His eyes slowly widen as he looks back at Sherlock. "No, you. No, just." He furrows his brow and grabs the book. He stares at the cover and narrows his eyes. "Wait a tick. How did you even get this? Dumbledore removed this book from the library, and then Hermione Granger swiped it." He turns to Sherlock. "You told me it was in the Restricted Section."
"It was in the Restricted Section. You didn't ask when it was." Sherlock reaches over and grabs the book from John. He narrows his eyes and returns to the page. "That Granger girl isn't the cleverest person in the world."
"No, I suppose you are, aren't you?"
"You're catching up, John. Excellent."
"Are you even listening to yourself? What you're suggesting?" He shakes his head and sighs. "Do you even. Jesus." He rubs his eyes and settles back. He keeps quiet after that, and Sherlock doesn't bother replying. He's turned his attention back to the book, flipping through a few more pages.
Soon, John sighs and drops his hands into his lap. He examines Sherlock, his concentrated expression, his fingers gliding against his lips, his pajama bottoms that cut off at the ankles. "He was the same age as us, Sherlock. When he went to school."
"Your point?" Sherlock lazily replies, not removing his eyes from the volume.
"My point is, Sherlock, look where he ended up. Look what happened to him." John scans him before lowering his gaze. He purses his lips. "Don't you know what this might do to you? I mean." He glances around and leans in. "You have to kill someone," he mutters.
Sighing, Sherlock gives John a quick glance before snapping the book closed. "Not a problem." He sets the book in the other's lap and picks up a few pieces of parchment. He holds them up to his nose.
John's eyes widen, and he gets on the edge of his seat. "Not a prob—no, Sherlock. This isn't right. You just can't go… kill someone. It's completely wrong."
Sherlock purses his lips and drops his paper. He slips out his wand from his robe and flicks it towards the dormitory entrance. "Muffliato." He turns and narrows his eyes at John. "I said it wasn't a problem, so it isn't a problem. I don't see what the big deal is." He sets his wand on his lap as he picks up the parchment again.
"You don't see what the—damn it, Sherlock." John bows his head, shutting his eyes. "We are talking about ending someone's life, or does that not matter to you?" He opens his eyes and stares at him. "Let me guess, it doesn't matter to you unless you get your answers to your stupid experiment? You will have to end a person's life. A breathing, thinking, walking, talking human being. How can you even discuss this subject with a straight face?"
"It's not like I'm going to commit genocide, John. If I'm lucky, I could get Mycroft when his back is turned." His parchment is immediately ripped out his hands, making him frown. He looks at John. "What?"
"Shut up, Sherlock. This is not okay. Not okay at all." He looks down at the parchment, shaking his head again. "Oh, here, 'interested to feel the effects of having just one'. Wonderful." He rubs a hand through his hair and crunches the notes in his hand. "'Interested'," he breathes out, pressing his fingertips to his forehead.
Sherlock carefully watches him as he lowers his hands. He lightly touches his wand. "Don't act as if you haven't wondered what it felt like, having a piece of yourself reside somewhere else. Don't act as if you question life after death, or you worry about what would happen if your life was put to a short end."
The blonde falls against the couch and pushes the parchment away. He crosses his arms over his chest. "I don't want to lose you, Sherlock," he says quietly, watching him. "I know how obsessive you can get, and I don't know if I can watch you do that." He frowns. "First, you say it's only going to be one, but, before you know it, you'll have seven of them, and I'll have to call you Lord Sherlock."
"Please, my name would be much better than that."
John cracks a smile and presses his head against the couch. "Stop that."
"Stop what?"
"Making me laugh. This is supposed to be a serious conversation."
"It's not my fault."
"No, nothing ever is, is it?"
"Correct."
Sherlock tilts his head and watches John, who stares back. Silence hangs in the air, and, soon, John turns away. He clears his throat and looks at the floor. "If you die, and you had one of those... things, do you expect me to bring you back?"
Leaning forward and pressing his lips to John's ear, Sherlock breathes out, "Of course."
John wakes up the next morning pressed to Sherlock's chest. He hears movement around the room, and he scoots closer, feeling the blanket being tugged, slightly over him. Sherlock's fingers drop to his shoulder and press into the skin, giving him a sense of reassurance.
The noise starts to die down, and John takes that as his cue to pop his head out. He's met with a half-lidded stare from his boyfriend, disheveled curls everywhere. He lets out a laugh and raises a hand, attempting to press them down. "Good morning."
"Good morning," Sherlock repeats, his voice barely more than a rumble. "I hope you've slept well."
He's about to reply, but anything of the sort leaves his mind when a Siamese cat gracefully leaps onto the four-poster bed, yowling loudly. John jumps and nearly falls off the bed. Sherlock laughs and sits up, reaching out and grabbing the feline. Pulling the cat into his lap, he coos and rubs behind its ears. "Good morning, Sebastian."
Sebastian purrs and shuts his eyes. John snorts and sits up, stretching the best he can. "Bloody cat," he mutters. Said cat is soon pushed into John's lap as Sherlock extends his legs and slides off the bed. The taller drops to his knees and gathers up loose scraps of parchment from the floor. John cranes his neck and watches him. "You going to eat breakfast today?"
"I might."
John nods and looks down at Sebastian. He scratches his chin before letting the thin cat creep to the pillow and nestle in the middle. Finding himself smiling, John turns and returns to Sherlock's attempt at tidying up. "I'll reward you if you did," he adds, getting up out of bed. He lazily brings the covers up to the pillow, smoothing them out with a hand as he walks around the corner. He leans against the post and crosses his arms over his chest.
"Intriguing," Sherlock says, the ends of his lips curling. He goes over and opens the trunk at the foot of the bed. He stares at the contents and begins to shift some items around. "Obviously, you'll have to stop by your dormitory to get a change of clothes. Hold Billy." He shoves the skull into John's hands without waiting for a reply.
John blinks and holds the skull out, studying it. "Alright." He glances at Sherlock, who had fished out a fresh set of clothing and had begun to change. Pursing his lips, he looks back down at the skull. The item seems to breathe against his touch, and the slight sounds of whispering came from inside. John furrows his brow and lifts up the skull, peering inside the eyeholes. For a second, he sees a glimpse of icy-blue eyes looking back at him, and he about drops the object from surprise.
Sherlock shoots him a look. "Hey, now. Careful." He turns back to his mirror on the nightstand and sniffs, adjusting his tie. "Can't replace that. One of a kind."
John stares at the other and nods. "What? Oh, yeah, yeah." He cradles the skull in his hands and studies it. "One of a kind," he mumbles, curling his fingers against the bone.
Soon, Sherlock strides across the room and stuffs his hands into his robe pockets. "Are you coming?"
The skull seems to smirk as John carefully places it back in the trunk. He closes it and makes sure it's locked before following behind Sherlock. "Of course."