Merlin makes a magical love potion for a nervous young lord and his apprehensive bride-to-be. Mayhem ensues when several others also help themselves to the brew. Comedy/Romance, and just a little angst before the end. Not particularly graphic, but rated M for safety. Arthur/Merlin SLASH.

For those who don't recognize the title, "Love Potion Number 9" is the name of a very old rock and roll ditty, written in 1959, which has been covered between then and now by countless bands and soloists. (Perhaps most recently by Robert Plant in 2009.)

Chapter 1: The Potion

It was all Merlin's fault, naturally.

As usual, he only had been trying to help. If he had stopped to think about it, he would have remembered Gaius' numerous warnings not to use magic for anything other than the direst of emergencies, like saving Arthur bloody Pendragon's life, for example, or rescuing Uther Pendragon from the arms of a trollish wife (not that he deserved rescuing, mind). In this case, nobody needed rescuing-at least, not at first.

He even might have remembered Gaius' second-favorite warning, one that he applied to everything from recipes for cough syrup to legal documents and official edicts: always read the fine print.

It all started when Guinevere made an unexpected visit to Gaius' workroom for some of the sleeping medicine he made for her mistress, the Lady Morgana. (It had become apparent to everyone in the royal household that the poor girl's nightmares were worse than usual these days.) As it happened the court physician was out; he had gone down to the cellars where he stored certain imported herbs and spices, but Merlin was busy at his worktable, grinding peppercorns into a fine powder that was making him sneeze.

When Gwen asked him for an extra bottle of sleeping potion, Merlin asked her, through his sniffles, why she needed it, and for whom.

"It's for Lady Linnet," Gwen replied, sighing. "You know, the pretty girl who just arrived at court. She's to be married tomorrow, and she's terrified, poor thing."

"She's marrying young Sir Gareth," said Merlin knowlegeably, hunting for a handkerchief. "His father's a local baron. But Gareth's one of the kindest of the newly-knighted squires-I should know, he's the only one of Arthur's knights who doesn't make fun of my ears-and he's good looking as well, or so all the girls say. Why should she be terrified?"

"She hasn't seen him since she was five years old and they were betrothed, that's why," Gwen murmured. "She doesn't know him, and he doesn't know her. I know that's the way the gentry do things, but I think it's cruel. He's extremely nervous, and she's truly frightened."

When Merlin looked bewildered Gwen stamped her foot with exasperation.

"Merlin, for pity's sake! Don't you know anything about, uh, what a...oh, I don't mean to be indelicate, but...you know, what a couple does on their wedding night?"

Well, of course he knew. It was natural that he should know about the facts of life-what country boy didn't? But why should the Lady Linnet be frightened about something troubadours and poets were constantly alluding to as the most blissful thing in the world?

Gwen threw up her hands with frustration at his ignorance and stalked off with the two bottles of sleeping potion.

In the end, he had to go to Gaius for enlightenment, and what followed was a mildy embarrassing exchange. No, he was not asking Gaius about these things for personal reasons. Yes, he knew all about the birds and the bees. No, he did not need to have The Talk. Yes, he had once gone through Gaius' library and read everything Aristotle and all those other dead Greek and Roman chaps had to say on the subject of, erm, reproduction-but certain differences between a man's experience and a woman's were still a bit of a mystery to him.

Once Gaius had stopped guffawing into his ale, he sat Merlin down and showed him some anatomical charts.

"I already know all that stuff," Merlin protested.

"Then what is it, precisely, that you're asking me?" asked Gaius, beginning to sound as exasperated as Gwen.

"Why should Lady Linnet be so frightened about her wedding night that she's asking Gwen for some of Morgana's sleeping potion?"

"Ah!" said Gaius, and proceeded to explain one major difference between a man's virginity and a woman's.

"Oh," said Merlin, a little shocked. "It's no wonder she's upset."

"I'm surprised you didn't take this question to Arthur."

Arthur? Merlin would be about as likely to take this sort of question to Arthur as he would be to march into Uther's throne room stark naked and tell him all about his magic whilst juggling two plates in the air, blindfolded. If he was uncomfortable talking about the facts of life with Gaius, how much more uncomfortable would he be if he were talking about them with that insufferable prat of a crown prince, who would fix him with those incredibly blue eyes, grin sardonically with those full, dusky pink lips, and, damn it to bloody hell, call him an idiot as usual.

"I fancy Arthur could tell you just about anything you wanted to know on the subject of, well, ladies."

"Erm, I'd really rather not have to ask him, if you don't mind," muttered Merlin uncomfortably.

"It's simply one of those experiences women have to endure that we don't," Gaius went on as Merlin forced himself to stop thinking about Arthur by envisioning unpleasant things, like those disgusting leeches his elderly guardian sometimes used in his medical work.

"What makes it worse, naturally, is the fact that she scarcely knows the boy," Gaius added a moment later.

"Poor girl," Merlin said absently, his mind already moving on to other matters, like how to get out of cleaning Gaius' leech tank.

"Just be grateful you don't have to worry about any such thing, yourself," Gaius murmured in a fatherly voice. "Now, about that wretched leech tank..."

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Later that afternoon, Merlin was sitting in the courtyard trying to look inconspicuous (lest someone ask him why the crown prince's manservant was lolling about doing nothing), taking deep breaths of fresh air and recuperating from his ordeal with the leech tank, when he caught sight of Gwen making her way across the paving stones. She was, in fact, carrying a basket laden with embroidered fabrics and walking behind a pretty, red-haired young woman in a gown of finespun green wool, a gold necklace around her throat and a small jewel danging from each ear.

He had only seen the Lady Linnet once before and from a distance, upon her arrival at court, but he recognized her instantly. Now, he noticed, her face was pale and drawn, her expression anything but happy. Halfway across the courtyard, they encountered young Sir Gareth, who bowed to his lady and kissed her hand, but otherwise looked anything but delighted with the idea of their upcoming union.

"You see," Gwen said to Merlin when she returned to the courtyard, having escorted Lady Linnet to her chamber. "She's miserable just thinking about her wedding. Oh Merlin, it's so unfair! She's such a sweet girl, and now she's stuck with that po-faced boy for life."

"He's not po-faced, Gwen, he's just a bit shy," Merlin said defensively. He rather liked Sir Gareth, who had always treated him, as well as the other servants, with a gentle courtesy. "And if you ask me, he looks just as apprehensive as she does."

For whatever reason (perhaps she was concerned about her own matrimonial prospects) Gwen was clearly in a very bad mood. She strode out of the courtyard not long after, making the excuse that she had to see to a torn hem on the gown that Morgana was wearing to the wedding ceremony.

As soon as Gwen had disappeared, Merlin stood up, stretched, and walked back to Gaius' workroom.

"I've got to go down to the lower town for some supplies, my boy," the silver-haired physician announced as Merlin came in. "You'll keep an eye on those medicines, won't you, while I'm gone?"

He jerked his chin in the direction of several small pots simmering on the hearth, and Merlin nodded vigorously, but as soon as Gaius had made his exit he raced to his little room, where he carefully unearthed his book of magic from its hiding place, and turned to the pages marked "love potions."

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It took a great deal of skimming through various recipes and arcane spells, some inscribed in a very crabbed and shaky script, before Merlin finally found the type of potion that he wanted. The instructions for preparing this concoction-the ninth-were quite lengthy, although fortunately written in large letters and a bold, firm hand. There were also various postscripts in much finer, smaller writing that Merlin did not bother to read.

According to the description, this was a powerful love potion designed to awaken both desire and romantic affection in the hearts of whoever drank it. It tasted like blackberry wine, and was guaranteed (by no less than three venerable wizards from three different countries, who had written glowing testimonials) to work like a charm. One full goblet, drunk by both the gentleman and the lady in question, resulted in a lifetime of love (carnal and spiritual) and devotion.

If any potion remained after the couple had drunk their fill, it could be diluted with wine. The diluted potion, if consumed, produced a much milder effect: the drinker would simply experience three nights of passionate longing for the first person upon whom he or she set eyes after drinking it.

Merlin found a large bowl and then rummaged through Gaius' stores of herbs, flowers, tinctures, and elixirs to make certain he had everything he needed before setting to work. The potion was not particularly difficult to make, although the number of ingredients was astounding. Once they had been infused together and then heated, they turned a most remarkable shade of blue-almost the color of that prattish prince's eyes-and Merlin held the heavy bowl steady whilst he carefully recited the required spell: drincan...lufu...aefre.*

The mixture bubbled and sizzled, and its color suddenly settled into the dark reddish-purple of a good, well-aged wine. Merlin poured it hastily into a flagon, tied a piece of leather over the top to protect it, and hid it in his room. It would hardly do to allow anyone to find it. If King Uther were to hear of it, it would mean his head on the chopping block, or a very thorough and very public roasting. And if Arthur were to hear of it...well, perhaps he wouldn't have Merlin executed, but he would certainly be horrified to know that his manservant was a sorcerer, and would almost certainly send him away. The thought of which Merlin found he could not bear, impossible, arrogant, supercilious, overbearing prat that the crown prince often was.

Besides, it was his destiny to remain by the prince's side to protect him, wasn't it?

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Gaius kept Merlin busy for the rest of the afternoon, running errands in the lower town and then delivering medications to various inhabitants of the castle. He had barely enough time to see to the mucking out of Arthur's stable, wash up (it would not do to wait on the prince that evening smelling of horses), and bring yet another of Gaius' sleeping potions to Morgana's chambers. As none of these potions appeared to work very well, Gaius had fallen into the habit of creating a new one almost every other day.

"You'll be in attendance at poor Linnet's wedding tomorrow, won't you, Merlin?" Morgana asked the moment Merlin appeared. She said nothing about his having entered her room without knocking; this was something nearly everyone had gotten used to by now, with the exception of Uther.

"Of course he will," Gwen said, raising her eyebrows. "He doesn't have much of a choice, as Arthur will be there. But yes...poor Linnet."

Merlin reflected that things would be looking up for both poor Linnet and her groom, once they had drunk the love potion and were given a little privacy.

Gwen was engaged in brushing Morgana's long, dark hair, but she gave Merlin a little smile as if to apologize for her negative mood of the early afternoon. Merlin smiled back and set Morgana's sleeping medicine on the table by Morgana's mirror.

"I don't suppose this will work any better than the others," Morgana sighed, pressing her hands to her alabaster brow. "But you never know, and I don't want to hurt Gaius' feelings. Well, it's late, so you'd better be off, Merlin, and see to his lordship. Honestly, you'd think the boy would know how to undress and dress himself by now."

"Yes, wouldn't you," Merlin said somewhat acidly as he made his exit. He could hear both girls sniggering as he closed the door.

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"You're late," said Arthur dryly as Merlin skidded into the room, miraculously avoiding collision with the pieces of unpolished armour pointedly set out in the middle of the floor.

"Sorry, sire," Merlin replied automatically, locating the prince's night shift and draping it over the back of a chair near the hearth to warm it. The heavy window curtains were already partially closed (did he actually do that himself?) and all of the candles save those by the great canopied bed had been extinguished.

"I'll need the new embroidered tunic for that wedding tomorrow," Arthur muttered, kicking off his boots. "And you'll be in the official ceremonial garb of the-"

"No," groaned his manservant despairingly. "Not again! I thought-"

"No Merlin, you didn't think, as usual," snorted the crown prince. His well-shaped mouth with its full lower lip was quirked upwards at one corner, and Merlin could see that he was making an effort not to laugh. "There's no way you can get out of wearing it. And the hat."

"I know you think it's funny, Arthur," Merlin replied grimly. "But you don't have to wear it."

Arthur made no reply but he grinned as he stationed himself near the carved stone hood of the fireplace and waited for Merlin to unfasten his shirt.

The process of preparing the prince for bed had become second nature to Merlin, and he made short work of it, unfastening the leather belt, unlacing the shirt, and then lifting it over Arthur's head. Arthur unlaced his trousers himself, letting them fall in a heap as Merlin courteously averted his eyes, and, stepping out of them, held up his arms so that Merlin could pull the fine linen night shift, now properly warmed, down over his muscular shoulders.

Merlin gathered up the fallen articles of clothing and bundled them under his arm to add to the pile of laundry he would have to see to the following morning.

"I'll want a bath tomorrow, early," Arthur said absently, as he squinted at the fire in the hearth. "At dawn. Before the wedding."

"Yes, sire," said Merlin, edging towards the door and wondering how he could budget his time so as to see to the laundry and prepare the prince's bath. "Will that be all?"

"Yes, Merlin," replied Arthur, yawning and pushing his fair hair back from his brow. "Just be certain your official tunic is clean and pressed, or you'll have my father after you with a horsewhip."

"What you mean is, he'll order someone else to come after me with a horsewhip," muttered Merlin. "Could I at least go without the hat?"

"Sorry," Arthur said with a smile that was also a bit of a smirk. "Father insists on it. All of the servants will be in ceremonial attire; it seems the Lady Linnet's family carries more prestige than poor old Gareth's. Even if that wasn't the case, you could hardly go to a wedding looking like this."

His eyes raked his young manservant from the cap of unruly black hair to the toes of his scuffed brown boots, taking in the coarse homespun linen shirt and brown jacket that hung loosely on his exceedingly slender frame, and that ridiculous, annoying neckscarf, faded and shredding along the edges, carelessly draped but calling attention to a long, pale throat.

"In other words, it's better to look a laughing stock," Merlin was saying with resignation.

"Oh stop whinging, Merlin, you idiot," the crown prince snapped, his tone of voice suddenly going from amused to sullen. "Bad enough that I'm going to have to look at Gareth's gloomy face tomorrow."

"I take it he doesn't want to get married either."

"What do you mean by either? But no, I don't think he does. He's barely acquainted with the girl." Merlin could hear a kind of slow-burning anger in Arthur's voice. He was no doubt thinking of his own future, when he would be handed over in marriage to some young woman of his father's choosing.

"Now get out; I'll see you tomorrow at dawn, sharp," he added, turning away from Merlin with a scowl and stalking to the window, where he propped his elbows on the sill and peered at the dark night sky through the narrow opening in the drapes.

As Merlin descended the stairs, the bundle of Arthur's clothing under one arm and bits of his armour under the other, it occurred to him that the crown prince's stellar good looks and military prowess did little to make up for his utter lack of consideration with regards to his overworked manservant.

* I apologize for my misuse of Old English vocabulary.