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Surprisingly enough, it was actually Diluc who had brought up sneaking into the library’s Restricted Section.
"I thought mischief was my thing, 'luc?" Kaeya had teased. "Tired of being the goody-two-shoes, are you?
Diluc just returned Kaeya's smirk. "Many adventurers have tried to find this claymore for years, but none have succeeded. And, well, Sir Karl—"
"The silver fox?"
"—saw me eavesdropping on the other adventurers who were talking about it and pulled me aside. Said that while he admires “the younger generation's curiosity,” we'd do good to learn where to get better information. Said the Wolf's Gravestone does indeed exist, but the reason why none of the other adventurers have been able to find it is because they're all too dumb to know how to read—"
"Oh, gods! Haha!"
"—and that the location of the claymore is stated in one of the books in the library's Restricted Section."
"Right. And you're sure you aren't just getting your naive little leg pulled, dear brother?"
Diluc had merely thrown a most delicious challenge Kaeya's way. "Well, don’t you want to find out?"
✧ ✧ ✧
The Wolf's Gravestone. A legendary claymore imbued with otherworldly power, guarded by the spirit of a great beast, and the reason why the two young men of the Ragnvindr household are now hunting after some book.
The Headquarters’ library is massive, though they’ve both spent enough time here that they can figure their way around well enough, even in the mysterious Restricted Section.
They maneuver their way around the tall bookshelves quite aimlessly, not really knowing where to start. The books in this area aren’t arranged like the rest of the library. In fact, there doesn’t seem to be any rhyme or reason to how they’ve been arranged at all.
"What's that crusty old librarian doing allowing this place to be in such a mess?"
"Manners, Kaeya."
Diluc rolls his eyes at Kaeya who simply shrugs his shoulders, and with that, they split off.
“The Wolf's Gravestone....” Kaeya mutters to himself, raking his eyes over the rows and rows of books. Kaeya sighs to himself, starting his tedious search.
Tapping a gloved finger along the spines of books meant only for the use of the highest ranking members of Ordo Favonius, he quirks a brow as something in particular catches his eye. It's crammed far back in the shelf, and dusty; dustier than even all the other ancient books housed in this library. Its hardbound cover is plain except for the book's title embossed with a crimson foil so dark Kaeya probably would have missed it had the low light from the sconce not made the title shine chrome.
From the next shelf over, Kaeya hears a whispered “ah-ha!” and, slyly pocketing his finding, peeks his head around to see Diluc’s triumphant grin.
“Found it, then?”
Diluc holds up a proud hand, a thin little book in his grasp. He grins. “Right here. Exactly like Sir Karl said—“ Diluc cuts himself off abruptly and grabs Kaeya’s arm, dragging him behind the shelf immediately beside them.
A shadow cuts a menacing stripe on the hardwood floors in front of the library’s entrance, the bright lights from the outside hallway almost fully obscured by the returned librarian, an older knight who is as tall as the shelves and as dusty as the books they hold.
Kaeya grabs a bronze bookend and, with great precision, throws it to the far end of the library, the opposite side to where he and Diluc are hidden.
The librarian’s head snaps so sharply in the direction of the clanging bookend Kaeya has to muster all the willpower he can to keep from snickering, in his head conjuring up images of the squirrels that roam Mond who react just as twitchily whenever he purposely steps on twigs to make them jump.
When the librarian moves, so do Kaeya and Diluc. Kaeya blows a kiss to the knights outside in the hall stationed for tonight’s guard duty, whose mouths he had convinced shut about their little after-hours visit. Diluc rolls his eyes and just grabs Kaeya by the scruff of his neck, hurrying to leave the Headquarters, tonight’s mission a surprising success.
✧ ✧ ✧
"... first came into being when the mighty beast—," Kaeya mutters to himself, squinting at the faded text, "—spilled its potent seed onto the grass circle hidden in the meadows, and out sprung a long pale stalk and milky white petals."
The oil lamp on Kaeya's bedside table casts barely enough dim light for him to make out the illustration of an exotic-looking flower on the page, drawn to look as if it was dripping some sort of creamy liquid substance from its petals.
" ... so powerful were the effects of this plant that the person to first discover...."
Soft footsteps pad onto the floors of the hallway outside Kaeya's quarters.
"... an erection that lasted —forty eight hours?! Hah!”
Kaeya falls back onto his pillows, clutching his stomach as he chuckles quietly. At the first knock on his door, he swiftly throws the book beneath his bed, pulling his blanket up to his chest and feigning a yawn as Diluc peeks his head through the door.
"Kae? Did you fall asleep?"
Kaeya sits back up slowly, pretending to have only just woken up, and extends his limbs in an admittedly much needed stretch, his hours spent hunched over his book and indulging in its contents leaving his muscles stiff.
“Are you ready to go?” Diluc continues, grinning and eager. “Tonight, we might find something incredible.”
Kaeya thinks of the book beneath his bed, a particular passage dog-eared within it, and tilts his chin up. He nods. "Let's go."
✧ ✧ ✧
Wolvendom, no matter how dangerous of a land it is, lies right in Kaeya’s heart as one of his most beloved of places. Too many memories of him and Diluc, young and too stupid to feel fear, running around and looking for trouble.
Years later, Kaeya thinks as Diluc vanquishes a hilichurl they’d met on the path, and not much has changed.
“Not come by as many of those as usual, have we?”
“No,” Kaeya replies. “And that one was alone in its camp.”
The dilapidated arena at the heart of Wolvendom is huge and eerie, and not wholly unfamiliar. They jump down from the edge and make their way to the center. Kaeya looks at Diluc.
“Well?”
“Well,” Diluc replies, grimacing, “the book said this is where the Wolf’s Gravestone is.”
“Alright. And did the book say it was invisible, as well?”
“Oh, shut it. Obviously, it won’t be so easy to find. We’ve been here loads of times before and never seen it either. The wolf Andrius guards the gravestone, a spirit. Maybe it will lead the way?”
“Are we hunting for ghosts now, Diluc? Aren’t we a tad too old for this?”
“Listen—“
“I’m listening.”
“—the book didn’t exactly say how we could summon the spirit, either.”
A brow raises in amusement. “... I think I should congratulate Sir Karl on this marvelous prank.”
Diluc’s eyes roll. “Kaeya—“
A pained howl cuts through the air, and the two pause in their bickering, drawing their swords. They hadn’t come upon another human soul on their way here. Kaeya recalls the lone hilichurl.
“That didn’t sound far,” Diluc says.
“Come on,” Kaeya says.
Climbing back out the arena, they run a few paces just near the edge of it. The sound of two men arguing joins the howling.
“Come on, you idiot, just shoot it!”
“It won’t stop jumping!”
Kaeya nods at Diluc, both walking up to the hunters stealthily from the back and kicking them to their knees.
“Hey! What the fuck!”
Diluc presses the tip of his sword on the back of one hunter’s neck. “The wolves here are protected.”
Kaeya walks over to the injured wolf— no , the pup—which the hunters had been trying to capture.
“O-Oh! Well, we just—ah—oh, fuck this!” The other hunter reaches into a pouch, and before either Diluc or Kaeya can act, he throws the smoke bomb into the ground and both he and his comrade disappear in a puff of smoke.
Diluc curses. “Damn it!”
“Forget about them. We can report to the Grand Master about illegal hunters in our lands tomorrow.” Kaeya holds the pup in his arms. “It seems to be alright, just a cut on its leg. Probably grazed by an arrow.”
Diluc sighs. “Alright. Well, I guess it was a good thing we came out here after all—GAH!”
The pup leaps out of Kaeya’s arms, running off into the darkness as the winds start to whirl violently. The trees shake, leaves fly into the air, and a brightness emerges from the arena beside them.
“Diluc,” Kaeya gasps.
“There it is!” Diluc jumps back down into the arena, Kaeya soon following. Like a mirage forming into shape, a grand claymore materializes before them, its ghostly appearance shining a brilliant blue throughout the forest. “The Wolf’s Gravestone.”
Diluc reaches out tentatively, his fingertip barely a whisper away from the hilt before another powerful gust of wind knocks him back a pace. A bright— too bright —light shoots out from the center of the arena, blowing out wind so strong it threatens to make them fly, to cast them away from these grounds.
“What’s happening? Diluc?!” Kaeya grabs Diluc by the arm and pulls him out of the way just as a wolf, bigger than anything they’ve ever seen, lunges at him. It growls, prowling along the outer rim of the arena menacingly. “Andrius,” Kaeya breathes, the now icy air making his every exhale visible.
“The spirit of the north.” Diluc shivers, lifting his sword. “Prepare yourself, Kaeya.”
The battle starts right away, the great Wolf springing into action, leaping and clawing at them relentlessly.
Though Kaeya may be referred to as Diluc Ragnvindr’s shadow by many, never let it be said that he falls even a fraction lower than his brother when it comes to battle. They work together, perfectly synchronized, retaliating every brutal hit with a blow of their own.
The winds have gotten unbearably strong by the time the Wolf starts showing signs of even weakening, and they start to lose hope.
Until a cry from somewhere outside the arena catches the Wolf’s attention. The pup.
Suddenly, the biting winds calm, the temperature rises back to normal, and the great Wolf is... gone. Kaeya turns to the center of the arena and, instead of seeing the claymore they’d worked so hard to locate, locks eyes with Diluc instead. The Wolf’s Gravestone is nowhere to be seen.
“I’m sorry,” Kaeya breathes, sheathing his sword.
“Don’t be,” Diluc replies. He sends a tired smile Kaeya’s way. “It was never mine to take."
“You’re allowed to be disappointed, you know.”
Diluc shakes his head. “Perhaps I did wonder if I was worthy enough to wield it, but I think I always knew the answer. I think… that claymore belongs here, with Andrius.” Diluc pats Kaeya on the back. “Are you alright?”
Kaeya wants to slot his body against Diluc's, suggest that the chill of the winds still lingers and state that heat is best shared between two close bodies, but he holds himself back. Though it feels so unlike him to hold back from teasing, Kaeya knows there’s no need for it now. He thinks of the book under his bed.
“I’m fantastic,” Kaeya winks. “This was the most exciting thing to happen all summer.”
Diluc rolls his eyes, before a tender smile lights up his face. He chuckles. “Father will have a heart attack once we tell him what happened.”
Kaeya looks down at Diluc’s lips, then, and he really considers it, but pulls away suddenly just as the beginnings of a flush colors Diluc's cheeks.
“We’d best head home, then,” Kaeya says, a warm smile on his face, though there’s the barest hint of mischievousness behind his eyes.
Diluc stares at Kaeya for a second, like he really wants to roll his eyes but only because he wants to pretend he’s not currently flustered. Instead, he just bumps his shoulder against Kaeya’s, chuckling as the accomplishment from a successful (in his eyes) mission brings about the familiar warmth to his chest and ache in his bones that tells him it’s time to rest now. He nods. “Right. Let’s go home.”
✧ ✧ ✧
The day after starts with a morning so quiet in comparison to the chaos of the night before. The sun's rays have only just begun to kiss the dewy grass and trailing grapevines. Kaeya’s footsteps are light, not wanting to disturb the crystalflies fluttering about. His trek back from Wolvendom has proven… fruitful.
It’s funny, Kaeya thinks, how it all lined up so perfectly. The Archons must be some perverted bastards to have aligned his and Diluc’s interests this way.
The Tears of Boreas.
It was no guarantee this would be left behind. The book had said any number of treasures could be left by the wolf, its tears the hardest to earn. Yet, as Kaeya had found the Blossom as he’d returned early this morning, a vial of glowing blue liquid had materialized from within it. This vial now rests in Kaeya’s palm.
The final ingredient.
He grins.
✧ ✧ ✧
Crepus Ragnvindr, owner and Master of the Dawn Winery, and father to two infuriating young men, did almost have a heart attack when the step-brothers finally told him of what happened in Wolvendom.
Diluc respected the scolding more than Kaeya did, who’d only made faces behind their father’s back as he’d paced around his study lecturing them about recklessness and respecting old spirits and what if you two had been seriously injured?
In the end, though, Crepus had just pulled them to his chest with a great sigh, a deep hug, and, after a moment, great deep guffaws. “Such a handful, my boys!”
The smirk Kaeya had sent Diluc’s way was eventually returned as Diluc sighed in relief. Neither of them had expected their father to be truly angry, no, not really.
However, that still didn’t mean they were completely off the hook. Apparently, one of the knights guarding the Headquarters had finally tattled to the librarian who it was that had snuck into the Restricted Section those weeks ago.
“We’re grounded?!” Kaeya and Diluc react in unison.
Crepus raises a brow, looking down his nose at them. “Yes,” he replies, curt. “Grandmaster Varka was very disappointed in you two for disrespecting the Headquarters by doing what you did. So, you have to be properly punished for such childishness. You. Are. Grounded. That means you won’t be coming with me on the expedition to Liyue this coming weekend, either.” Diluc visibly shrinks in on himself. “You two will stay here and look after the Winery while I’m gone. I’ve already instructed Adelinde not to let you two out for anything other than your knight training, and no moment later.”
It really was not the harshest of punishments. Being housebound only for most of the day, afternoons spent working up a good sweat as knights in the city is just enough freedom for it not to feel stuffy. A week flies by monotonously, the worst of it being having to watch their father’s caravan ride off for Liyue without them.
✧ ✧ ✧
The late afternoon is characterized by its pleasant heat, with Diluc practicing his swordsmanship on the straw-filled dummies out in the courtyard, desperate to pass the time somehow. And Kaeya, cross-legged on the floor beside his bed, listening to the sound of Diluc’s sword hitting his target outside his window—the Tome of Desire clutched firmy in one hand, a deep crimson potion in the other.
It had been a difficult process. Having all the ingredients for a potion is next to useless when you don’t have the equipment needed to brew whatever, in Kaeya’s case, nefarious concoction you had in mind. However, Diluc has always been weak to Kaeya’s pouting, no matter how equally exasperated he is at Kaeya taking advantage of the fact.
“Well, whatever it is you’re planning, hurry, alright? I don’t know for how long I can keep the other Captains distracted.” Diluc had rolled his eyes, but acquiesced, because, for Kaeya, of course he would.
“Why, brother!” Kaeya had gasped, because he just can’t ever help himself. “Are you accusing me of being up to no good?”
The blank stare he’d received in return had kept him giggling all the way down to the market district where he’d had to hide behind a bush waiting for Grandmaster Varka to finish eating at Good Hunter’s. Timmie was kept quiet with a piece of Mora when the boy had come upon him, leaves stuck in his hair and being pecked at by pigeons.
Finally getting to the crafting bench had been exciting and nerve-wracking. One chance, that was all he could afford, with summoning and beating Andrius again being very unlikely.
Good thing Kaeya has always excelled in alchemy.
A knock on Kaeya’s door, followed by a slight creaking as Diluc peeks his head in, red tendrils of hair sticking to his damp forehead. “Kaeya! Supper’s almost ready.” He’s still a little breathless from abusing that training dummy.
“You should probably take a bath first, ‘luc.” Kaeya snaps the book shut, smiling. The potion in his other hand lies just out of Diluc’s view. “You stink.”
Diluc scrunches his nose. “Sorry if I didn’t feel like growing mushrooms locked up in my room all day. What are you reading that’s been keeping you from spending the day with me anyway?”
Kaeya stands and walks up to Diluc. He bops him on the nose. “Oh, nothing,” he sings. “Now, go! I don’t want my appetite ruined by your stench.”
✧ ✧ ✧
“Drink with me.”
Diluc lazily opens his eyes and barely lifts his head from where it lies on Kaeya’s mattress. Out from the chest at the foot of the bed, Kaeya reveals to him a bottle of the Winery’s finest.
“Father won’t be back for another week. The smell of wine on our breath will be gone come morning,” Kaeya continues.
Diluc says, “You know I don’t like wine.” He closes his eyes again then grunts as Kaeya slaps him on the belly.
“Good thing I have some of your boring grape juice as well, then!” Kaeya laughs, a second bottle emerging from the chest.
Diluc makes space for him on the bed, Kaeya left amused and incredibly fond at the way he fills the space like he owns it, and the deadpan stare he sends Kaeya’s way as first the bottle of wine is uncorked.
Diluc says, “I won’t ask how you acquired that.”
“We literally live in a Winery.”
“Father keeps a strict inventory.”
“And I,” Kaeya smirks, “am very aware of the fact that the workers want me to marry their daughters.” He takes a long swig at the bottle, not missing the scandalized expression on Diluc’s face as he swallows. “And that father trusts the workers enough to not double check the numbers.”
He shudders. This is his first taste of wine since their punishment had been laid out, and although he is by no means a lightweight, Kaeya already feels drunk.
This is really happening.
Diluc goes to grab the grape juice, but is blocked by Kaeya’s elbow. “Wait,” Kaeya murmurs, licking the stray droplets of wine staining his lips red. He reaches across the bed to get at his chest again, this time procuring a single copper goblet. “You’re not as much of a heathen as me, I know.”
“How considerate,” Diluc deadpans, “shall you serve me as well?”
Kaeya knows Diluc didn’t mean for that to be as suggestive as it is, but he keeps the idea filed away in his brain. Kaeya, in his excitement, is getting ahead of himself. But the possibilities are endless, now—or, they will be after tonight.
The grape juice is poured, the goblet is handed to Diluc, and Kaeya can feel his heart pounding in his chest. Diluc must feel the weight of Kaeya’s stare on him, heavy as an anvil, but he just lifts the rim of the goblet to his lips and, finally, takes a sip.
The potion is simply called Desire , and it’s the very last entry in the Tome of Desire. It is a very difficult potion to brew, not because the procedure is particularly hard to execute, but because it requires the very rare ingredient from an ancient spirit with the capability to kill all those stupid enough to seek it out.
However, its most important ingredient is the tears of whoever wants to be on the receiving end of the potion drinker’s desire.
Kaeya has pined over Diluc for years. And he has always felt that Diluc also... well. But Diluc is heir to a noble family, and responsible to a fault. His only weakness has only ever been Kaeya. Not brothers by blood, but perhaps close enough to be considered scandalous by the generations before them.
Well, Kaeya has decided: years of circling around each other has gotten tiring and, having celebrated his ascent into manhood just a few months prior, they are both too old for this.
If all he needs is a little push, Kaeya will be the one behind it. Mischief is in his nature, after all, right?
Diluc will understand.
The moment Diluc draws away from the goblet and swallows the dark liquid, he shows no immediate sign of being affected by the potion mixed with the tart juice that happens to be his favorite. Kaeya leans in expectantly, like a cat mewling over a saucer because it knows it’s about to be offered dinner by its master.
“Can you stop staring at me like that?”
Kaeya ignores the question; leans even closer. “How do you feel?” he asks, impatient.
Then, Diluc’s eyes widen, as if in realization. “You—!”
Kaeya sucks in a breath.
Diluc continues, “You tricked me into drinking wine!”
Kaeya chokes on air, watching as Diluc grimaces in disgust and aims a searing glare at the goblet in his hand. A long moment passes where Kaeya’s entire body alights almost to the point of pain, brought upon by the desperate need to suppress.
Diluc grumbles, put upon, and— there it is. A downturned gaze, scrunched up brows, and a bottom lip pushed out childishly.
He’s pouting.
Kaeya cannot help himself. Shoulders first tensing then relaxing in an awkward rhythm that jerks his whole upper body, he can keep it in no longer as his little giggles build up steadily and uncontrollably, until he’s almost falling off the bed as he lets out loud guffaws.
Diluc glares at him too, then; rolling his eyes only until, despite himself, he starts to feel laughter bubbling up in him as well.
“No, that is definitely not wine, silly boy,” Kaeya says, a wide, toothy grin straining his cheeks as bouts of laughter still take over him. “Although only you, in all of Mondstadt, would be so affronted by the possibility.”
“I’m more affronted by you tricking me with wine than the actual wine itself.”
“I didn’t trick you with wine, first of all, and second: you know you can just admit you can’t handle your alcohol, don’t you?”
A kick to Kaeya’s leg. Kaeya reciprocates. “Can you please stop saying that? Even Jean has started to believe—”
The change is so sudden, yet so subtle. Diluc’s eyelids peel back, his pupils dilate, and he hesitates for a moment. “K-Kaeya,” Diluc says. He sounds breathless. He gulps and the action looks painful. “What is this? What did you….”
Kaeya grins, elation mixed with anxiety swirling in his chest as devious as the potion settling into Diluc’s belly. ‘ Is it working now? Is it really?’ he wants to ask so badly despite knowing Diluc doesn’t have the context to understand. “Sorry to say, Diluc, but you were right,” he says instead. He leans closer, putting a hand on Diluc’s chest. “I have been up to no good.”
Kaeya means to tease just a bit more, see how Diluc reacts now that the potion’s effects must be spreading throughout his body. Kaeya should be irresistible to him now. Diluc should be positively, uncontrollably smitten.
But Diluc just shouts in pain, doubling over into Kaeya’s arms, heaving. The goblet clangs as it falls to the floor, dark violet liquid spilling out and seeping into the hardwood.
Kaeya freezes. Confusion sets in quickly, and is made worse as Diluc starts shivering. With considerable effort to stay calm, he wraps his arms around the other. “Diluc?” Kaeya says, gently.
Bare arms touch Diluc’s hot, thinly clothed back in a hug. Kaeya goes to address him again, but Diluc cuts him off with a sob.
Well, alright. Maybe Kaeya is panicking. Diluc’s body is heavy against his, and getting hotter by the second. Kaeya’s strong but he’s panicking and he’s thankful that they’re already on the bed, otherwise his now trembling body may not be stable enough for Diluc to rely on.
Kaeya, with all his intellect and all his wit, cannot think fast enough as he racks his brain for the words written in the gods-damned book beneath his bed—words he’s read dozens of times over the course of enacting his plan of making a potion. He recalls them, but, unfortunately, the words give him no answers.
Why is Diluc… hurting?
Kaeya comes up with nothing.
“Diluc? Diluc, I’m sorry,” Kaeya rasps, voice wavering as he becomes delirious with worry and guilt. His days sitting at a wooden desk with the basics of alchemy being taught to him are long behind him. Books became straw-stuffed dummies, pencil and paper turned into sword and shield, and he’s gone from writing on chalkboards to strategizing over time-worn maps.
But he’s never forgotten his lessons. He has a sharp mind, and a strong memory. And he knows exactly how bad it can get when alchemy doesn’t go as precisely planned. Did he mess it up? Where did he go wrong? Kaeya doesn’t know if the mistake he made was somewhere in the making of the potion—or if it was deciding to experiment with an old book he’d found already locked up in the Restricted Section of the Knight’s library, his own brother as his unconsenting guinea pig.
“I thought… I didn’t….” Kaeya whispers, and cradles Diluc’s cheek in the palm of his hand. Diluc whines. “I’m so stupid. Diluc—I’m sorry... I’ll try to figure out—!“
Diluc’s body jerks in Kaeya’s arms, a single, sharp movement where his whole body pulls taught like the strings of a lyre. Eyes rolling to the heavens, his back arches and the grip he has on the back of Kaeya’s tunic tightens.
Time seems to stop as Diluc opens his mouth and, finally, speaks.
“Kaeya,” Diluc moans, hips pressing forward and grinding on Kaeya’s thigh.
For the second time that night, Kaeya finds himself in shock.
This time however, when he recovers, it’s wry amusement that takes over him. He pulls back just enough to get a look at Diluc’s face, to which the other protests. With the hand cradling Diluc’s face, Kaeya brushes a thumb over a high cheekbone and in turn receives hot puffs of breath on his face as Diluc’s hips jerk.
“Oh gods,” Diluc heaves. “Kaeya… oh fuck.” His hips start moving erratically, as if of their own accord, seeking friction against Kaeya’s muscled thigh. “Dont—” Kaeya’s heart skips a beat as he listens, instinctively jerking back. Diluc pleads, “Please, don’t stop.”
Something powerful washes over Kaeya, like a sun-warmed tidal wave strong enough to drown him. He shivers, his heart beating in rhythm with the throbbing of his cock, then, desperately, he starts touching Diluc wherever he can, seeking hot skin through constricting nightclothes. Diluc still hasn’t let go, hasn’t stopped moving his hips.
His hands slip underneath Diluc’s loose tunic, and when Kaeya tickles his belly before moving up to brush over a peaked nipple, Diluc lets out a sound so loud and guttural before going completely still.
In the silence that follows, Kaeya is acutely aware of the feeling of sweat dripping slowly down his temple, and the beads of it atop his upper lip making him taste salt as he licks his lips.
“Did you just come?” he asks, in disbelief.
Diluc is eerily still for a short, tense moment before he moves, gripping the front of Kaeya’s tunic in a trembling fist. He growls, and it almost sounds like a laugh, dark and very angry. “Kaeya what the hell did you do to me?”
Kaeya raises his palms in surrender. “Well. Perhaps you weren’t wholly wrong to have been suspicious of your drink.”
“You drugged me?!”
“Does a potion count as a drug?”
“A potion?” Then, Diluc realizes. “What the hell have you been reading about in that damn book of yours? That’s it, isn’t it?”
Kaeya knows, had Diluc been in more control of his body at the moment, he would have definitely punched Kaeya across the face after he just grins and, infuriatingly, shrugs his shoulders. “Shouldn't have taken me to the library that night, Diluc.”
Diluc shakes his head. “Oh god, I can’t think about this now.” Tugging Kaeya closer, sharply, Diluc growls into his ear. “Take your fucking clothes off.”
Kaeya is treated to rough, unforgiving handling. As soon as he takes his shirt off, he gets the wind knocked out of him and can only take it as Diluc throws him onto his back, the other taking his place between Kaeya’s legs.
“Did you at least have the mind to prepare?”
No he didn’t. This wasn’t even the outcome he’d been expecting. But Kaeya is also a healthy young man. Kaeya answers by pointing to the drawer in the bedside table. “Not your first time, then?” he tries to tease, with just the barest trace of jealousy as Diluc leans over him and starts rummaging.
Skin to skin contact seems to be Diluc’s only source of relief from the potion’s spell, and Diluc wastes no time in pulling Kaeya’s loose pants off, his last remaining piece of clothing. Kaeya is given no chance to feel shy about his stark nakedness before his brother as Diluc follows suit and undresses hastily, slotting their bare hips together and sighing hotly at the contact.
Perhaps, had this happened under different circumstances, had the potion worked as expected and simply made Diluc smitten and not painfully desperate for sex, they could have taken things slower.
The heat now being shared between them where their bodies connect, Kaeya briefly imagines them gyrating slowly, imagines them touching lazily, indulgently. They could have taken the time to explore each other’s bodies more thoroughly to sufficiently satisfy the curiosity that years of pining had built up.
Diluc uncorks the bottle of oils with horribly trembling hands. From the tips of his ears down to his strong chest, a blush burns red. “I’m not naive, you know,” he huffs, shaky fingers now coated in clear, smooth, thick liquid. “I know how this goes. I’ve heard enough from the older knights boasting of their conquests. But I’ve never….”
Diluc teases middle and forefinger around Kaeya’s puckered rim, then finds he cannot bear to wait any longer and pushes both in halfway. Kaeya’s thighs instinctively draw together at the intrusion and subsequent pleasure of being opened up, albeit how hasty and inexperienced. Diluc’s solid body between them prevents them from closing together all the way.
Diluc pushes and pulls, caresses and scissors, gets Kaeya ready for him. Kaeya touches Diluc all the while; down his sides, across his chest, and reaching forward to feel Diluc’s sweat-slicked back.
The remaining oils Diluc uses on his cock. The tip kisses Kaeya’s rim as he lines himself up.
“Me neither,” Kaeya says, just as Diluc starts pushing in. “I’ve never.”
When Diluc bottoms out, he grunts and shuts his eyes, unmoving for the duration of his sudden and overwhelming orgasm. Kaeya has never been harder in his life as he feels Diluc’s cock throbbing and emptying inside him.
The desperate need returns quickly, however, and Diluc starts rocking into Kaeya’s body.
Diluc leans down and captures Kaeya’s lips, kissing him for the first time. Kaeya has been waiting for this moment his entire life with Diluc, and Keeya had always assumed it would be so much more dramatic, like in the raunchy books the housemaid’s failed to hide from him. But this, this is so much better. Kissing Diluc feels natural, not overwhelming, but like they were always meant to do so.
Diluc pulls away with moistened lips, then immediately dives back in just to bite Kaeya’s bottom lip. Their chests are wet with sweat, Diluc’s body almost unbearably hot and warming them both. Their bodies slide against each other, Diluc’s hips snap, and Kaeya cries out.
The next time Diluc finishes, Kaeya is right there with him.
✧ ✧ ✧
They lay side by side, skin touching as much skin as physically possible, panting.
“My cock feels like it’s on fire.”
“It’s truly a testament to my attraction and fondness of you that that ridiculous statement doesn’t turn me off.”
A pleasant ache permeates both their exhausted bodies, their muscles finally being allowed rest in their first moment of reprieve after several rounds of sex. The quiet is not awkward, but the ghost of a much needed conversation lingers in the hot air.
“You can’t have been blind to it, Diluc.”
Kaeya feels rather than sees Diluc cringe. Obviously, this is not the kind of bedtalk either of them had wanted to have after their first times.
Diluc hesitates. “I… hadn’t dared hope.”
Kaeya’s pulse quickens. Hope? Reeling from the underlying meaning behind Diluc’s words, Kaeya copes by asking a question.
“Can you blame me for trying to find a solution?”
“A solution? To what, pining? With an aphrodisiac? You could have just talked to me, idiot.”
“You could have done the same,” Kaeya counters. Guiltily, he adds, “And the potion—it wasn’t supposed to affect you so badly. It was only meant to give you a little— push.”
Kaeya turns his head and finds Diluc already looking back at him. The tension snaps and they start laughing.
“Archons, we’re ridiculous.”
Diluc nods in agreement, then gulps. He draws closer to Kaeya and kisses him, gentler than he has all night now that the potion’s influence on his body is no longer so violently potent. He murmurs, “Can you keep going?”
“I thought you said your cock was on fire?”
Diluc passes him the oil. Kaeya reaches between his legs to reapply, but Diluc simply shakes his head and stops him. “What are you— oh.” Kaeya feels lightheaded as Diluc rolls onto his stomach.
“Open me up,” Diluc says over his shoulder, cheeks bright and grin even brighter. Then, voice steady as the message he delivers, says, “I want this.”
A statement. Clear permission. A bit late into the session of several rounds of fucking to clear, but a relief to hear explicitly stated nonetheless.
Kaeya is without the help of a potion meant to keep stoked the fire of his libido, and he’s already come twice while Diluc had peaked at an impressive six. Still, it is a good thing, then, that youth works in his favor—that and the sight of Diluc bending over for him.
Kaeya has never moved faster in his entire life. The vial of oils almost slips from his grasp and Diluc laughs, then says, “Slow down, idiot,” before gasping out a moan as Kaeya’s finger finally breaches.
“Fuck,” Kaeya curses. “I can’t tell you how many times I’ve dreamt of this. You’re opening up so easily, ‘luc, I— Fuck.”
When Kaeya slides in, it’s to an amazing heat and tightness.
“Wait for me, Diluc,” Kaeya pants as he starts pounding. “Don’t come until I tell you.”
“Gods,” Diluc moans, driven crazy by Kaeya’s blunt words, and, Gods, the stretch. “I, I can’t. Kaeya.”
“Wait for me,” Kaeya growls, feeling a heat pool in his belly. His hips smack into Diluc’s ass at a brutal pace. “Diluc.” Kaeya reaches beneath Diluc’s body, between his legs. Diluc’s cock is heavy and throbbing as Kaeya starts to pump. “Now.”
Kaeya feels an impossible tightness, then black bursts from the edges of his vision. Through the ringing in his ears, he faintly registers Diluc whispering his name, over and over.
✧ ✧ ✧
Diluc’s arms are wrapped around Kaeya’s waist, chin leant on the other’s shoulder as Kaeya lies on his back, the Tome of Desire resting on his chest as he reads.
“The potion was only supposed to make you incredibly drawn to me. Sex, of course, was a very likely possibility; but not because the potion forced you to or else suffer immense pain. Desire is the name—not Fuck Until You Feel Like You Got Beat Up by the Gods Themselves. ”
“You know, with how you fucked me after I bent over for you, you’d think you were also under the potion’s spell. You weren’t so gentle with me either.”
“Are you complaining?”
Diluc thinks about how Kaeya had him spilling onto the sheets, climaxing twice in succession as Kaeya had refused to let up and only adjusted his grip as he’d continued pounding.
Diluc doesn’t reply, only bites one of Kaeya’s dusky nipples.
Kaeya continues, “Did I mess up the potion? I followed the instructions perfectly. And I’m more talented at Alchemy than even you are.”
The nipple gets bitten once again. The air stills as Kaeya continues to read in silence and Diluc simply basks in the afterglow. After a moment, Diluc speaks. “I am still mad at you, Kaeya,” he says, sleepy but no less serious. “You know you went over the line with what you did tonight.”
“I know,” Kaeya whispers.
“We should go to sleep,” Diluc says, to which Kaeya agrees.
Burrowing together under the blankets, Kaeya extinguishes the oil lamp so only the moonlight bathes over them. In the quiet, Diluc speaks again.
“Kaeya?”
“Yes?”
Diluc turns over onto his side, closing his eyes after softly yawning. “I don’t regret anything.”
✧ ✧ ✧
Kaeya had debated whether he would return the book. Since the first night, alone in his bed giggling at the shenanigans he’d just gotten into with Diluc, the scandalous book in his hands, a devious plan brewing in his mind. Kaeya, he cannot deny, loves to cause trouble. He loves to cause headaches for people unnecessarily just because it’s fun. But he does move on eventually, say sorry, and fix what he needs to.
You’ve had your fun. Return the book.
By now, Kaeya has read the book a dozen times over. He has committed to memory all the most interesting information (with a book as ridiculous as this and a mind as ridiculous as Kaeya’s, there is a lot), but he knows he has to return it eventually.
Either it will collect dust guarded by the equally dusty librarian at the Knight’s Headquarters, or, in the future, it will fall into the hands of another annoying teenager.
You’ve had your fun. Return the book.
But he can’t. Not yet. Not until he figures out why….
Kaeya feels the phantom heat of Diluc’s heaving breaths on the skin of his neck, hears the heated pleas, remembers the pleasant ache in his body after a full night of marathoned sex. He remembers how desperate Diluc had been, remembers how he himself had felt his heart hammering on his chest as he’d looked upon his brother with worry.
Why had the potion affected Diluc so strongly?
Today had brought him wandering through the Whispering Woods, away from the Winery and the city, with this question echoing in his head. Not too many people visit Starfell, with its valley leading only to a lonely beach at the end of it. The Statue of the Seven at the heart of it had been in such a neglected state when he’d passed it that even he had felt compelled to clean it up a bit.
He hadn’t wanted to go to the lonely beach, though, even though seclusion had been his goal in coming to these parts of Mond. Hot sand doesn’t agree with him, not like the comforting feeling of grass beneath his bare feet. He sighs, now, where he sits on a grassy cliff, with sturdy bark against his back. The long tree branches and their leaves shade him from the sun.
The book lies open on his lap, with the crashing seas sprawling in blue beyond it. It’s displaying the last page, Kaeya having finished reading it just a moment ago. Nothing. No hidden answers to be found—not like sheer frustration could have made words magically appear just to appease his curiosity.
Salty air fills Kaeya’s lungs and his head hits the bark as his body relaxes.
So is that it, then?
Return the book.
Always so damn stubborn, Kaeya lifts the book to eye-level, scrutinizing it just once more. The last page on the left and the inside of the back cover to the right. Kaeya harumphs in frustration, and this time when his head hits the bark, it knocks the wind out of him a bit due to the force with which he’d jerked his head.
That, thankfully, pulls him out of his little tantrum.
He rubs the back of his head. “Ow,” he whines, and he starts to laugh at himself. His other hand had landed on the book, and he starts feeling the smooth paper on his fingertips subconsciously. As he rubs back and forth, his finger snags on the slightest of bumps. Kaeya’s brows furrow.
There, so close to the hinge it would almost be unnoticable, is the edge of a layer of paper atop the back cover: a pocket. Kaeya digs his nail into the opening slit, as you would a knife to a letter. It seems the seam of the pocket had stuck to the cover due to the book’s old age, disguising its existence and making the back cover look completely flat.
Kaeya knows there could just be nothing inside, that it could just be an unused feature in the book bereft of any notes and that he doesn’t actually have a reason to be excited. So, with this in mind, he almost whoops out loud as he finally peeks in. A folded up piece of paper.
Kaeya’s fingers shake as he pulls the paper out and unfolds it. The quality of it is different from the rest of the book’s pages which have yellowed in shade and frayed at the edges. This paper is still white as a shell, and crisp save for the lines indicating where it had been folded. Kaeya’s eyes scan it eagerly. There’s only a very short passage written on it.
Kaeya’s grip goes slack and the book falls to the ground, cushioned by the grass. The paper is still in his hands, though Kaeya seems to see right through it. No, surely he’d read that wrong.
Kaeya shakes his head, listens to the squirrels knocking acorns on boulders in the distance; pink noise helping him calm down and refocus. The paper crinkles as he reads again.
Beloved’s Desire.
The potency of the potion will be increased tenfold when given to the brewer’s Beloved. A Beloved is a person who—
Kaeya looks between his legs to the book lying on the grass. It had landed front side up, and the plain cover simply containing the book’s title now looks so much more intimidating. The Tome Of Desire.
Kaeya wipes the dirt off his trousers as he stands.
✧ ✧ ✧
It’s strange, almost uncanny, how normal life continues to be even after a night of fucking out their (unbelievably, thankfully reciprocated) long-repressed feelings. But they are Mondstadtians— even Kaeya, in his heart, he’s realised— and they simply go wherever the wind blows them.
Kaeya hears the clanging of steel against steel as he walks closer to the Knights’ training yard. Right in the pit, sparring against Grandmaster Varka himself, is Diluc.
Right as Kaeya reaches the very edge of the circle, Diluc’s sword hits the ground with a brutal clang!
“You’re improving, lad,” Varka says, nodding in approval. “You almost got the upperhand on me this time. Kaeya, how generous of you to show up to training today.”
Diluc turns sharply where he stands and lights up as he comes face to face with his brother.
Varka continues, turning to fully face the unashamed latecomer as well, “And how fortunate that you arrived right as the sun is setting. I recall your father saying you were only to be allowed out of the Winery for training with the knights.”
“Would you believe me if I said I got lost on the way from the restroom?”
Varka sighs, defeated. “I am much too lenient with you two.”
The young squires to the edge of the pit have already begun packing up equipment, the day coming to a close. The other knights roll their shoulders, easing their strained muscles.
Diluc stretches his arms over his head as he walks beside Kaeya. Warm orange casts beautifully onto Diluc’s youthful, aristocratic features. Kaeya bumps their shoulders.
“How was training? You must be improving—I think I saw a single bead of sweat on Grandmaster Varka’s brow.”
“Maybe you’d know if you’d shown up,” Diluc admonishes.
Kaeya laughs.
Diluc continues, “Also, I talked with Sir Karl again— “
“The hot older knight?”
“Can you please stop saying that every time I mention him? Anyway, yes, and he asked me about the Wolf’s Gravestone.” Kaeya raises a brow, and Diluc shakes his head. “I… I told him we didn’t find anything.”
Kaeya gasps. “Diluc Ragnvindr lying?”
Diluc elbows Kaeya’s side. “Oh, come on. I just… he spared us, you know. Andrius. I don’t think we would have come out of that fight alive had we not saved that pup.”
Kaeya nods, understanding. “You don’t want anyone else to try looking for the Wolf’s Gravestone,” he states.
“No I don’t. Andrius and the wolves, they deserve peace.”
Kaeya takes Diluc’s hand in his. “Come. We wouldn’t want Adelinde yelling at us for coming home late.”
✧ ✧ ✧
“Did I tell you about the triple-breasted mermaids, yet?”
Diluc shrugs off his vest, folding it neatly onto a chair to be picked up by the maids. “Yes.”
“What of this amazing creature, half-horse, half-man.”
“What? That just sounds like typical childish fantasy.”
“—and its perpetually erect horsecock, which was thick as an adult man’s arm.”
Diluc stubs his toe on the leg of his dresser as he whirls around, blushing madly at Kaeya. “How can you just say that so casually?”
Kaeya shrugs, smirking. “How can you still act like such a green young boy when you’ve had your cock up my ass?”
Diluc takes a seat at the foot of his bed, starting the task of unlacing his high boots. “I’m banning you from reading that book tonight. Not that it matters since you’ve most likely memorized the entire thing,” he grumbles. At the answering silence, he throws an inquisitive look at Kaeya.
“I’ve returned the book,” Kaeya states.
Diluc nods. “So you snuck back in again?”
“No.”
“Sorry?”
“No, I didn’t sneak back into the Restricted Section.”
“Then how—”
“I stood over the edge of the barrier and threw the book onto the other side.”
Diluc finishes unlacing his boots. His shoulders start to shake.
“Didn’t hear a landslide of books, so I don’t think I hit anything.” Kaeya thinks back to him throwing a copper bookend across the room and successfully distracting an old librarian, all those weeks ago. “Must be my impeccable aim.”
Diluc hits Kaeya’s chest with an open palm, laughing out loud. “You’re ridiculous!”
“Yes, but you love me, still, don’t you?”
The words are deliberate.
“Yes, I do,” Diluc rolls his eyes, grinning boyishly, completely unaware, but wholly truthful.