Actions

Work Header

Enzymatic

Summary:

Sanji and Luffy didn't have much success foraging in the island jungle, but once they start heading back to the ship, Sanji begins to feel...strange.

Part of Zaira's Lusan Love Week, this is for Prompt 7: Free Day!

Notes:

(See the end of the work for notes.)

Work Text:

This island was going to be the death of him. After leaving Punk Hazard, the crew had come across an uninhabited jungle island on their way to Dressrosa, and decided to anchor to look for some additional supplies, both for the infirmary and for the kitchen. 

But now, it was seeming like it might have been more trouble than it was worth. Sanji had been sent with Luffy to explore, and trying to keep up with his rubbery captain was hard enough as it was. The thick vegetation and sprawling vines certainly did not help. At least he had worn long pants to keep the brush from scratching him, but his arms were still taking a beating in the short sleeve floral shirt he’d worn to try to stay cool in the steamy jungle. He was beat, in all sorts of ways. They hadn’t found anything worth hunting or foraging after hours of searching, and it was starting to get dark. 

“Oi, Luffy!” he shouted up at his captain. “Let’s just head back. I hope the others were more successful than we were…”

Luffy yelled his agreement from the canopy, and flung himself back down to the ground right in front of Sanji, startling him with the close landing. But the closeness was fine. He’d always known Luffy to be touchy and clingy. And while most of the time Sanji would tolerate it to a point then pry himself free, lately, he found himself letting Luffy do whatever he wanted. And not hating it. The touch was comforting, and for now he was choosing to take that at face value. And choosing not to remember the filthy dream he’d had about the man the previous night. 

His captain followed behind him as they backtracked, walking normally for a few paces. It didn’t take long, however, for rubber hands to stretch forward, reaching over his shoulders to grab his chest. Luffy slingshotted himself onto Sanji’s shoulders, making the cook lean dangerously far back, then lurch forward with the force, having to use a considerable amount of strength to not fall over. 

“Can I sit like this?”

“Should’ve asked before you almost knocked me on my ass,” he grumbled, but rested his hands on his captain’s ankles anyway. He let Luffy play with his hair and wiggle around; he was sturdy enough to support whatever idle movements Luffy felt like making. 

They’d not even made it halfway back when Luffy pointed down at Sanji’s left hand, which still held the foot dangling over his shoulder. 

“What’d Sanji do to his hand?”

Frantically, he looked down at the appendage in question, and noticed a small scratch there. Thankfully nothing severe—he hadn’t even noticed it himself—though it did look pretty red and blotchy. 

“Probably just all these fuckin’ branches and shit, it’s nothing.”

This seemed to satisfy Luffy, who went back to swaying and swiveling from atop Sanji’s shoulders. 

By the time they were nearly back to shore, Sanji had noticed he was starting to feel…strange. His head was burning up and his limbs were feeling like cooked noodles, more so by the minute. His breathing was becoming laborious, and not just because of the thick humidity of the forest. 

“Lu’y, I ‘eed to ‘ut you down.” His tongue was sluggish, not keeping up with everything he wanted to say. Sanji registered alarm, but only distantly. 

“Eh?” 

His knee buckled with his next step, making the decision for him, and the two of them tumbled onto the web of underbrush. 

“Sanji?!”

He sat up, freeing Luffy to stand with the motion. Sanji was too dizzy to stand himself, head spinning like he’d had too much sake and not enough food to go with it. He held out his arms in front of himself, and noticed that a considerable number of the scratches he’d acquired—including the one Luffy had pointed out on the back of his hand—were now angrily irritated, with the redness spreading further from the scratch itself than before. 

Sanji dragged his gaze from his own arms up to Luffy, who was looking down at him with a puzzled frown. As soon as their eyes met, Luffy reached down, grabbing him around his back and under his knees and taking off in a dead sprint towards the edge of the forest. 

What had Luffy seen?

Sanji’s mind was…oddly detached. He knew enough about what was happening to know he should be concerned, but couldn’t bring himself to care. All he could focus on was the feeling of the strong hands under him and the solid chest next to him, and he let himself relax into the hold. The sound of Luffy’s breathing right next to his ears fed fuel to his fever and sent twinges though his chest and stomach, right down to his cock. He was half hard in his pants as Luffy bounded out of the jungle and onto the beach, arousal building below his navel. 

The hand under his knees stretched around to support his back as the other reached out for the Sunny’s railing, Luffy’s momentum launching them towards the deck. Sanji basked in the warmth of being pressed into Luffy’s bare chest, increasingly limp in his captain's grasp. Once Luffy landed on deck, his shouts for help should have startled Sanji. It should have worried him, should have impressed some sense of urgency, but it seemed too distant to matter. He heard only the frantic steps of Nami and Brook, the two that had stayed on the ship, as they came running out on deck, and kept his face tucked into Luffy’s collarbone. 

“What’s wrong with Sanji-kun?!” Nami shouted. The concern in her voice would have made him swoon, but right now, Sanji’s head felt like it was full of freshly cooked rice. Warm and heavy and soft, content to be held in Luffy’s arms. 

“I don’t know!” Luffy tried to explain what had happened, but was sorely lacking in any critical details. Sanji could hear everything that was said, crisp and clear, but was too busy trying not to completely melt. His skin felt so hot against Luffy’s. 

“Whatever is wrong, we should bring Sanji-san to the infirmary,” Brook directed. 

He felt Luffy nod before bounding up the stairs three at a time and bursting down the infirmary door. The handle rattled with the force of being slammed against the doorstop. Luffy set him down on the cot slowly, gently, and Sanji hadn’t expected the tenderness of the gesture from his typically rough captain. 

However, once he was away from Luffy, the intensity of his symptoms picked up. He was impossibly hotter and prickly, like he had pins and needles all over his body. And, where before he was only uncomfortably aroused, now his cock was painfully hard. He moaned, pawing at his pants and squirming on the infirmary bed. His eyelids felt heavier than lead when he opened them and turned to Luffy, hoping he would understand. When Sanji saw his lovely Nami-san and the skeleton there, ice flooded his veins, clearing his mind just enough to feel fully embarrassed at his state. 

“I—, I don’ know wha’s wrong wi’ me,” he whined, still squirming from the irritation. His clothes were too rough on his skin, his body was too hot. Sweat on his brow made his bangs cling to his forehead. 

“I’ll go find Chopper-san!” Brook poofed into his ghost form, floating away and letting his physical body slump into one of the chairs against the opposite side of the room. 

Sanji knew he needed something. Every nerve in him was fidgeting, clawing at him for it. If only he knew what it was. For now, the friction his pants provided against his throbbing erection felt too good to stop, even if he had two of his crewmate’s undivided attention. 

“Sanji-kun, what did you get yourself into?” Nami’s exasperated voice floated to him, more asking the universe the question, not him. Below the layers of heat and bristling tension, Sanji wanted to ease her worries. But everything was overshadowed by the oppressive pain and blinding arousal spreading through him as he squeezed his thighs together, agonizing. 

Then he felt a hand over his, stilling them from roaming all across his chest. 

Luffy.

The realization that the wanton moaning he was hearing was his own voice came several seconds too late, but he still clamped his mouth shut. 

“It’s okay, Sanji. We’ll fix it.” 

Luffy’s determination assured him, cutting through the thick fog in his mind. Sanji clasped his other hand over Luffy’s, sandwiching his captain’s hand between his own, grasping at the lifeline. Holding Luffy eased some of the torrid pain that was lighting his body on fire. 

“Luffy.” Sanji didn’t recognize his own voice pleading the name. He opened his eyes again, not realizing he had closed them, and saw Nami whisper something in Luffy’s ear. In that brief lucid moment afforded by Luffy’s touch, he could only feel burning shame at letting Nami see him like this. Hot and hard and helpless. Luffy nodded, and Nami left the room without looking at him again, leaving the two of them alone. 

Minutes felt like hours, days, as Luffy sat next to him. Even with Luffy’s hand clamped tightly between his, the tingling pain intensified. He needed his clothes off, he needed to find some release, but he didn’t want to let go of Luffy. 

“Sanji, what’s wrong?”

The question was beseeching as it was infuriating. Sanji didn’t know what was wrong, and even if he knew, he was unable to say or do anything about it himself anyway. He whined again in frustration, rocking left to right on the bed, cycling his legs up and down on the mattress, thighs brushing his sensitive cock. The pain was evolving to pure agony, white flashing behind his eyelids as he screwed them shut. 

Luffy tentatively placed his other hand on his thigh, and Sanji keened. The additional touch was a morsel of salvation. He was so hard, and his shirt was completely soaked through. He let himself wail, hoping to ease a fraction of the pain. 

Just then, Chopper came into the room, his frantic voice sounding muffled to Sanji’s addled ears. Luffy turned to him, explaining but having the wherewithal to keep both hands on Sanji. Thank God. Sanji was too focused on trying to relieve any of his pain, practically flailing now, making the simple wooden frame of the infirmary cot creak with the force of it.

Chopper hopped up to the bed, standing next to Sanji. The movement caught the blonde’s attention, and he stilled and lolled his head to the side, willing himself to focus on what his doctor had to say. 

“Sanji, you’ve been infected with a powerful aphrodisiac,” Chopper explained, wringing his little hooves together. “A… sometimes deadly one.”

Well that didn’t sound good.

“You…well, you need to have an orgasm, or your body temperature will keep rising until… You could die, Sanji!”

An orgasm? Chopper was looking back and forth between Sanji and Luffy, wringing his little hooves together and leaning side to side. He could tell their nakama was genuinely worried, but he also couldn’t grasp the gravity of it. All he knew was pulsing, painful need and the searing heat trapped between his body and the bedsheets. Sanji turned to his captain just in time to watch the lightbulb go off, and the urgent scowl appear.  

The Strawhat doctor jumped down from the bed, and one of Luffy’s hands left his thigh as the other started to pull away from underneath where Sanji had it clamped to his chest. Even just the gentle tug, the hint of Luffy leaving him, sent fiery fractals through his entire body. The cold, clammy heat of undiluted fear.

“NO!” He shouted, louder than he meant. “Luffy—!” 

Words failed him, his eyes pleading with Luffy instead. He needed him to know, to stay.

His captain tilted his head, eyebrows pinched together in confusion. Sanji had to cobble a sentence together to save his life. It seemed more impossible than any fight he could remember having, having to trudge through the delirium and smothering desire. The helplessness he was forced to succumb to, cutting through the fog in him to settle heavy at the base of his throat, only added to the struggle. He swallowed, tongue darting out to wet his lips. 

“Need you.”

It was high with strain and effort, dry and weak. The determined set to the rubber man’s jaw, the curt nod, felt like a being wrapped in seafoam. He’d stay. Sanji wanted to worship him as he came around the foot of the bed, faintly hearing the click of the infirmary door opening and closing. They were alone. Sanji pulled his knees up to his chest, spreading his legs to give Luffy room to climb between them. 

The blonde was panting, whimpering with every short, ragged breath. He arched his back, throwing his head against the pillow, feeling the bed dip as Luffy climbed up to settle between his spread legs. When nothing happened for a few seconds, he craned forward, searching for the reason. 

His captain was worrying his lip, hands hovering just above Sanji’s shins where they were held in the air. Though he couldn’t remember much in his current state, Sanji was certain he’d never seen Luffy look so conflicted. His body was suddenly bypassing his brain, taking hold of those hesitant hands and placing them both on his asscheeks, forcing Luffy to squeeze him there. 

Just a taste of relief was all it gave him, but that was all it took for Sanji to find his words again. 

“Please—!”

“I want to help Sanji, but…” Luffy trailed. Agitated and impatient, the knowledge that Luffy had never done anything sexual was far from the forefront of his mind. However, the spirit of the hesitation still made it through to him. Luffy didn’t know what to do. To help himself, he needed to help Luffy. 

Sanji lurched forward and threw his hands around Luffy’s neck, pulling him forward into a sloppy kiss. Luffy huffed in surprise, but eventually relaxed into it. Once Sanji found a rhythm he was sure Luffy wouldn’t abandon, he released his grip on Luffy’s neck and began to fumble with his own pants. He pulled away reluctantly to shimmy the garments off his hips, throwing them onto the floor as quickly as possible. When he yanked his shirt open the buttons clattered the floor. But he was free now to peel the drenched dress shirt off, sitting naked in front of Luffy. Sanji watched with hazy, lidded eyes as Luffy took him in, also hesitantly shedding his red button-down vest. The air on his skin was only cool for a second, not even making a dent in his agony. As soon as he was free of his clothes, Sanji pulled Luffy towards him once more. His captain let out a contented hum as Sanji drove his tongue deeper into Luffy’s mouth. 

Keeping Luffy occupied with their kiss, he began to blindly unbutton Luffy’s shorts, pulling them down with his underwear and letting them rest at his knees. Luffy hardly seemed to notice, but eventually pulled back to look questioningly at Sanji. 

“This is helping?”

The kissing, his hands on Luffy’s skin, it was all helping to clear some of the haze in his mind. But he needed more. He nodded frantically. 

Yes, I need—” He pulled Luffy’s hands towards him, placing them on his chest. “Touch me,” he begged, hoping even a tenth of his desperation made it through. But the rubber man cocked his head to the side, clearly confused. 

“How?”

“Just don’t stop.”

Frustration—sexually and otherwise—was boiling over. Sanji barely had the wherewithal to speak at all, much less explain sex to Luffy. He reached around Luffy’s torso, wrapped his hands under his shoulders and flipped the two of them so Luffy’s back was against the clinic cot, and Sanji’s corded thighs were straddling his narrow hips. At least Luffy had managed to follow that one direction, and kept his hands on his pecs. Their hardened erections were brushing, and the heat made Sanji’s head swirl. He ground down onto Luffy’s cock, the friction feeling like finally breaking through the ocean’s surface just before his lungs would’ve given out, and he let his head roll back in bliss. 

He didn’t notice one of Luffy’s hands had been removed until he heard clattering from the desk. The rubber man had stretched to grab a small bottle from the surface, and knocked a few other things over in the process. 

“Chopper said you might—”

His eyebrows shot up when he realized what that bottle was. “Give me that!”

Sanji snatched it from Luffy, not caring if he caught his fingers in the process. He flung the cap off the bottle and squeezed until lube was oozing off his hand onto Luffy’s tanned, toned abs. 

“Shishi, that’s cold!”

Sanji ignored him, tossed the bottle to the side, and reached around himself with his slicked-up hand, sliding two fingers up to his entrance. Luffy was looking up at Sanji curiously, still just one hand on his chest. 

“Luffy, touch me—!” 

Jarred from his amusement by Sanji’s anguished call, Luffy scowled with focus and returned his other hand to Sanji’s chest, palming and grasping at the muscle. As Sanji desperately shoved his fingers deeper inside, working himself open, he was dismayed to find little relief at his own actions. At this point it was simply a means to an end. That end being: bouncing on Luffy’s dick until he came. He was dripping sweat and precum, sweltering. 

Sanji let his eyes flutter, focusing on grinding their cocks together while grinding back onto his fingers as quickly as possible. When Luffy’s fingers experimentally pinched at his nipples he outright screamed, the sensation sending shockwaves through him. Luffy gasped at Sanji’s response, and the blonde looked down to see that mischievous smile. At least Luffy was starting to get the hang of it. 

“More!”

His captain obliged, pinching and scratching and roaming. Sanji wasn’t ordinarily so sensitive, or so loud, but all of his visceral reactions seemed to spur Luffy on more, which he could only be grateful for. As soon as Sanji could fully fit two fingers inside himself, he pulled out and shifted himself forward so the tip of Luffy’s cock was at his entrance. It would have to be enough. The stifling heat throughout his body was boiling him alive. 

Sanji couldn’t afford to be swayed by the apprehension on Luffy’s face, his own unease distant enough not to matter. But he still kept his eyes locked onto the man below him as he moved. He grasped Luffy’s cock with his lubed hand, giving it a couple rough tugs before holding it steady and lowering himself down. His asshole was still so tight, but he forced himself down anyway, the burn of the stretch at least more satisfying than his fever. Luffy moaned out as Sanji speared himself on his cock, hands gripping hard enough to bruise Sanji’s hips. 

Even before he was fully relaxed, Sanji began bouncing in Luffy’s lap, forcing lewd moans out of himself each time Luffy’s cock went deeper. Those strong, rubber hands stayed on his hips, and Sanji watched Luffy’s eyes go wide with fascination, pupils blown out. 

The first thrust deep enough to hit his prostate made Sanji’s vision black out, but he still wasn’t feeling any relief. If anything, the closer he got, the further away he drifted. It was like scratching an itch but never getting it to go away. He had to keep scratching, driving down onto Luffy with abandon. 

He still needed more. 

Sanji leaned forward, clutching at Luffy’s shoulders, siding his hands to his neck, around the back of his skull, all while keeping a punishing rhythm. The malleable rubber skin under his palms gave him an idea, and forced his body into action. He sat back up, going back to letting gravity help him land on Luffy, and pulled at the rubber man’s skull. Luffy stretched forward at the neck, his head obediently following Sanji. 

The blonde’s jaw clenched, teeth grinding together with a possessive need as he looked into Luffy’s eyes, seeing only curiosity there. No more hesitation. He used one hand to grab his pulsing, aching cock, and the other to guide Luffy’s mouth to his tip. 

Luffy’s lips plunged him into a chilling pool of pleasure. While Sanji meant to give his poor captain a moment to adjust, his sheer need overwhelmed him. He wanted to drown in the ecstasy, to suffocate in it. He fisted the hair at the back of Luffy’s neck, shoving him further down on his cock, messily forcing himself into Luffy’s hot, wet mouth. 

Luffy gagged at the sudden intrusion, drool dribbling down his chin. Muffled cries spilled from around the edges. He was absolutely wrecked with his lips stretched taut around Sanji’s cock, cheeks filled out and bangs splay across his face. The sight was a drop of lucidity splashed on the surface of Sanji’s frenzy. Just enough for panic to clench his lungs. But the fever persisted, inundating him once again with an insatiable instinct to keep going. He kept his pace, kept his hand at the back of Luffy’s neck, kept his eyes trained on Luffy’s as they drooped, lidded and unfocused. 

All the broiling heat in his body migrated to his lower stomach, collecting at his base. Sanji was chasing his orgasm, harder and faster and still it seemed to be miles away from him. Luffy’s hands slid, grasp faltering at his hips, coming to rest on his thighs and tapping gently there. 

Luffy groaned around the cock in his mouth as he came inside Sanji, not even getting a moment to ride his orgasm over the edge. The blonde kept his brutal pace, fucking Luffy’s mouth, fucking himself on his cock relentlessly as Luffy’s cum leaked out of him. Chasing and chasing, running from the heat and towards it. 

Tears were running down Sanji’s cheeks, and he scanned down to see Luffy looking much the same. He was so close. Impossibly close. He just needed…

In his haze, Sanji guided Luffy’s hand to his own balls, forcing Luffy to clamp down around them. 

Sanji came, hard and fast, still holding Luffy’s head down on his cock. He rode Luffy’s dick through it, waves of white hot pleasure crashing over him. It was combustion, exploding and sending pulses of cool relief through him. The euphoria was unmatched, higher than he’d ever been. The orgasm itself was almost just as good as feeling the inferno fade. It didn’t seem to end, and Sanji was going to take everything he could get. 

The bliss only started to dissipate once Luffy went slack beneath him, head snapping back onto the pillow of the clinic cot and taking in gulping breaths, his chest heaving with the effort. 

Shivers wracked Sanji’s body once his cock was exposed again, no longer surrounded by the warmth of Luffy’s mouth. He shuddered, letting the last of his life-changing, life-saving, orgasm fade. Luffy’s cock was going flaccid beneath him, and he finally pulled off, cum dripping onto the sheets. 

He didn’t know what else to do besides collapse next to Luffy on the cot and give them both a chance to catch their breath. 

Luffy’s panting next to him was the first thing he noticed, and when Sanji finally floated back to himself, he threw himself off the edge of the cot. He scrambled backwards, knocking over the chair, bumping Chopper’s desk and rattling the bottles of medicine on the shelf.

“Luffy, I—!”

The memories of their intimacy slammed into him with the force of Kuma’s Hand of Liberation. He had been so rough to Luffy, he had basically…

“Sanji’s feeling better?”

Luffy sounded raw, likely from how merciless he had been with his throat. But he still sounded cheerful, relieved, even. Sanji didn’t deserve that. He was torn between wanting to look at his captain, to make sure he was okay, and wanting to look away, not worthy of looking him in the eyes. 

“I—I mean, I am, but Luffy, I was so—I’m so sorry!” he cried, voice cracking. New tears spilled down his cheeks, still following the tracks of the ones that had only just dried. 

“I, I…” He never meant to do something like that to Luffy, to anyone! “I couldn’t help it, I didn’t mean to.” Sanji trailed off, looking down at his hands. They were shaking, just like his knees. His legs buckled beneath him, and he slid his back down the desk, landing inelegantly on the floor with a thud. His hands flew to his hair, pulling and ruffling his golden locks. 

“Oi! Sanji?” Luffy shot up off the cot, clambering over to where Sanji was crumpled against the desk. He could sense Luffy’s hovering, uncertain what to do. Sanji was cornered. He gripped tighter at his roots, and Luffy’s hands came up to cover his, gently prying his hands free from his head. His breath was coming quicker, shorter now. The adrenaline, the come down, the anxiety all avalanched, burying him. But Luffy was determined to free him, even if he didn’t deserve it. Sanji was a disgusting, vile person, having done that to Luffy, he deserved to suffer, he deserved to—

“Sanji!” Luffy shoved his face in front of Sanji’s, mere inches away. “What’s wrong? You said you were okay. Do you still need me to touch you?”

“NO!” Sanji surprised himself with the volume of his response. But Luffy didn’t jump, didn’t budge, didn’t remove his hands from overtop of Sanji’s. He didn’t release them even when Sanji pulled. “I don’t—I’m not—” Shit. He had to settle down, Luffy needed him to explain. The tears overflowing down his cheeks only seemed to fall faster. He wouldn’t even know what Sanji did was wrong. But he was shaking harder, and the words couldn’t make their way past his throat. 

Luffy urgently wrapped his hands around Sanji’s naked, trembling form and lifted him back to the cot, eerily reminiscent of before. Instead of giving him space, Luffy crawled up onto the cot with him, sitting behind him and curling himself tightly around the blonde’s back. It didn’t make him feel constricted like he imagined it would. Rather, Luffy’s breath tickling his ears and his heartbeat thumping against his back made it easy for Sanji to calm down. He brushed his fingers gingerly through Sanji’s hair until his stuttering breaths had smoothed. 

After what felt like an eternity, Sanji took a deep, shaky breath.

“Luffy,” he started. “I’m so sorry. I… did I hurt you?”

“Sanji didn’t hurt me,” Luffy whispered in his ear. “You’re okay, right?”

He swallowed thickly, and nodded. “What I did to you, it… it wasn’t okay. Don’t… don’t let anyone do something like that to you ever again.”

Luffy snickered, and Sanji turned to the side, trying to look his captain in the eyes from over his shoulder. “It’s not funny! I’m serious, Luffy!”

“Sanji couldn’t help it! Plus those weird plants would have killed you otherwise.” Luffy’s chin nestled heavier against his traps, nuzzling into his neck. “Besides, that was really fun.”

“You—fun?!” Sanji pushed forward, separating them enough to finally look Luffy in the eyes. He looked desperately back and forth between those rich, dark brown eyes, trying to see if he was lying. But he should have known better than anyone: Luffy never lies. Those eyes only smiled at him, lifting the strangling weight from his shoulders. It made him feel small. “...Really?”

“Yeah! Can we do that again sometime?”

Sanji nearly choked on his own tongue, feeling his cheeks flush in spite of himself. “What?!”

He would be lying if he said he’d never fantasized about being with Luffy, the number of wet dreams he’d had about his captain was frankly embarrassing, and he intended to take the secret to his grave. 

“I liked touching Sanji like that. And I liked the way Sanji touched me.”

Luffy always made everything so simple. Maybe too simple. 

“Well,” he fidgeted, “It won’t be quite like that, but…Yeah, I guess we can do that more.” Looking at Luffy’s blinding smile, he couldn’t unsee the debauched, spit-smeared face he had donned only minutes ago. 

“Don’t feel bad, Sanji. I wanted to help,” he stated matter-of-factly as he inched around Sanji and off the cot to stand in front of him. Luffy placed his hands resolutely on his knees, laughing heartily. “I’m happy you’re okay now!” 

It was all he could do to laugh along with him.

Notes:

Thank you for reading and sticking with my very delayed LuSan Week posting! Well over word count goal for this one--AGAIN--but you know I gotta squeeze in some post-nut angst. Dare I say I'm even a little proud of this one? I'm sure I'll catch a typo or wording thing on a future reread... Even with the considerable delay, I'll count finishing at all a success, all things considered. I had a great time going through these! Please comment if you enjoyed, and go give some love to the other works in the collection!
find me you know where (on tumblr).

Series this work belongs to: