To everyone who has reviewed, favourited, and followed – the support for this story has been amazing so far, and I cannot thank you enough. Once again, a special mention to Caldera32 who has pulled out all the stops and been a fantastic beta, allowing me to post this early.

I hope you like the next chapter, feedback as always is very welcome.

Chapter 4 Swords and Potions

Arthur looked over the training grounds, searching for the gangly figure who was supposed to be joining him and was already late. He tapped his foot impatiently against the soft ground, releasing the scent of wet grass, and scanned the horizon once again but there was no sign of his tardy servant. As the king waited he played with the stopper on the water-skin; he'd almost emptied the contents onto the ground several times but had righted the vessel at the last moment. With a sigh he looked down at the object he held in his hands. Merlin's perpetual inability to arrive on time was not helping matters. The doctored water-carrier remained full and the king began to pace.

These personal training sessions were designed to help the hapless servant protect himself during bandit attacks; Gwaine and Leon had been keen to offer their services but Arthur had wanted the project all to himself. The king enjoyed this; he liked anything physical and would lose himself in the mock fights. He loved the exhilaration of his heart beating faster, the pull and ache in his muscles as he pounded his body and let his mind be free. It was the one time he could forget the pressures of being a king and just enjoy the flow of movement, the rhythm of his sword as his arm effortlessly carried out the cuts and thrusts he'd been taught as a child. These skills had become so ingrained that his body instinctively responded to any challenge without conscious thought. Often Arthur could anticipate his opponent's intentions before they'd even thought of what to do and therefore parried most blows easily.

The royal had tried to impress upon his servant that it was just like learning the intricate moves of a dance – this did not help matters and the lanky man would wrap himself in knots and trip over his own feet. Merlin looked as comfortable holding a weapon as the king holding a scrubbing brush. His repertoire was limited and he lacked the strength and expertise to wield the blade proficiently. The only thing in his favour was speed; he actually got better when the pace picked up and when Merlin acted instinctively he was often successful. Strangely, Arthur could not always predict what the servant was going to do and there had even been a few occasions when Merlin had managed a feat some of the knights struggled with - to get the upper hand against the king. How he did it was a mystery; the moves were unorthodox but somehow it worked. When Arthur thought about it, Merlin had excellent reactions; he was the one that sensed things before anyone else. He seemed to have a second sight - the monarch had lost count of the times he'd been manhandled to the ground by a mass of lanky limbs, averting a danger he had not even been aware of. The irony was, for someone who hated hunting, Merlin had the eyes and ears of a hawk; but for all that, the grace of his namesake eluded him.

As the warlock rushed towards the training grounds he could just make out the armour-clad king stomping up and down, kicking divots in the ground. Great, the prat was in a temper. Merlin sighed; he was already drained from lack of sleep and hoped the royal would not make him run around the field to warm up before practice. Arthur had got it into his head Merlin ought to increase his stamina by doing laps but as far as the sorcerer was concerned running should be reserved for when one was late (which he frequently was) or when something horrid was chasing you (again, something that happened far too frequently for the servant's liking).

Being outside was usually rejuvenating; the breeze on his face, the sounds of the birds and the smell of wild herbs. The fresh air should make him feel better, only he was here to fight so it didn't. Merlin hated violence and wished disputes could be settled more amicably; he knew it was necessary for the knights but he could obliterate a kingdom with a blink of an eye and a wave of his hand if he chose to. He had no desire for such things. He only killed if he had to; taking any life saddened him and was only done as a last resort. The warlock wondered why he should be given so much power when half the time he used it for such trivial things. The rest of his time was spent keeping The Once and Future King free from harm and that did require effort; the task would be so much easier if he did not have to hide his gift. He longed for the freedom to study and hone his craft – to reach his true potential. Sometimes he feared he would lose against Morgana. He had more innate power, but when was his chance to practice? She had every waking hour at her disposal; no magic was out of bounds, no act too low, she was ruthless and cared for no one – this was her greatest strength and it was all to his detriment. Such thoughts were not helpful and he pushed them aside. Arthur had insisted on these lessons and Merlin inwardly smiled. It was the only way the royal could show he cared – never with words but through action, deed, and punches.

All too quickly the warlock was dressed with a breastplate, and could see the angry face of his sovereign through the slit in his helmet. Licking his lips, he swallowed and flexed his fingers against the pommel of his sword – let the fun begin.

After half an hour Merlin felt the vibration travel up his forearm and into his aching shoulder as he blocked yet another one of Arthur's blows. He'd barely recovered before he had to prevent a further attempt, this time aimed low, causing the sorcerer to flex his knees dangerously and unbalance himself.

"Stop bobbing up and down, you need to float," barked his opponent.

And I'd love to see you fly! Thought the warlock, but stopped himself, not wanting his gift to respond to such wishes. It would not do to have the king blasted backwards into the dirt no matter how tempting that may be.

"Rotate your hips and transfer the power through your arm."

Useful as this information was, the servant was concentrating on keeping upright. He was flagging and his legs were wobbling uncontrollably. When he lunged his knees would lock momentarily, like being stuck in mud, and it got more difficult to get up. Sweat stung his eyes and the sword slipped in his hand. Arthur's onslaught was relentless; blow after blow delivered with precision and incredible force coupled with helpful tips that Merlin was in no fit state to offer retorts to - though several choice words were mumbled under his breath.

They'd been sparring for three quarters of an hour and the royal had stopped speaking; instead there was only the sound of clanging metal and grunts and groans. They'd both removed their helmets – they were simply too hot and restrictive. The king had a look in his eye and Merlin knew the knight was somewhere else – on a battle field, a skirmish with bandits, a personal hell - not on the training grounds. The slashes got harder and more vicious and it took all of the warlock's concentration not to let his magic intervene and stop the battering.

"Arthur!" He panted, "Stop!"

The monarch did not hear him; he lifted his sword and sliced through the air, making a whooshing sound.

"Arthur!"

Merlin would have to slow time to get out the way.

Arthur was shaken out of his trance by the scream of his servant. He looked up just in time to see the man before him crumple, clutching his thigh.

"Merlin!"

The king speared the ground with his sword and sprinted toward his friend. Merlin was lying on his back like an upturned beetle; grasping his left leg, face contorted in agony. The monarch skidded to a halt and dropped to his knees. He franticly peeled Merlin's fingers away, searching for a break in the thin fabric and braced himself for the blood that would spurt from the wound – there was none. His palpation slowed when all he could feel was taut muscles, plaited cords spasming beneath his touch.

Arthur rocked back onto his heels, letting his hands flop to his sides. "I thought you were hurt," he said curtly.

"It does h-hurt!" By way of demonstration the servant shrieked again and rolled onto his side, still clutching the offending limb.

"It's a cramp, and it's your own fault; if you'd got here on time and warmed up properly this wouldn't have happened," seeing the younger man was still in pain the royal relented.

"Here," Arthur said, "you need to stretch it." With that, the blond knight stabilised the writhing servant's pelvis with a firm right hand as his left grasped Merlin's knee, bending it 90ᵒ. Taking the rest of the weight through his forearm the royal levered Merlin's heel towards his buttock and pulled the quadriceps muscle tight. Stretch over, the king released his servant.

"Better?"

"A bit," the invalid said with a meek shrug of the shoulder, "thanks."

"You need to drink," the king held out the doctored water-skin.

Merlin looked at the offering, he was thirsty but did not want to move so he shook his head, "I'll get something later."

"NO! You have a cramp and need fluids," Arthur insisted a little too urgently. "Now drink it, that's an order." Damn it, why do have to make this more difficult than it already is?

The servant just stared for a moment.

"Of course, Your Highness." The felled man snatched the water-skin, took a large gulp and spat most of it out. "That's disgusting – has something died in there?"

"MERLIN!" The monarch snarled, "That's my own personal water-skin, it has the royal seal."

The dark-haired man flinched, "I'm just saying..."

"Well, don't - just drink it, all of it," he snapped, fixing the younger man with a hard glare.

Merlin gave the king a pinched smile, raised his eyebrows, and tipped the remaining fluid down his throat.

Arthur bit his lip as he saw the servant's Adam's apple bob up and down. He was struck with a sudden urge to swipe the container away but before his hand had even twitched, Merlin had finished. The servant pointedly wiped a sleeve over his mouth and held the water-skin upside down to show it was empty, then tossed it back towards the king.

The deed was done.

"Is everything alright Sire?"

Both men jumped and turned to see Gaius standing serenely before them.

"Oh, hello Gaius, I didn't see you there," the king said like a child caught with his finger in the cake mix, "I have just finished giving Merlin his training."

"So I see," the old man responded dryly.

"Is there something I can help you with Gaius?"

"Yes Sire, as a matter of fact there is. I was wondering if Merlin could be relieved of his duties so he can help me dispose of some out-of-date medicine?"

Panic hit Arthur. I need to question him; I need the truth! The royal calmed. "Is that really necessary? Can't it wait? I am in need of Merlin's services myself this evening."

"Well, Your Highness, the properties of preparations can change over time," the physician licked his lip and proceeded with caution. "It is not safe to keep them over a month. Some lose their potency, some get stronger or even toxic and others can become volatile and dangerous." He leaned forward, "Need I remind you of the explosion that took out most of my previous place of study?"

There was something about the way Gaius spoke that could make the royal feel like a twelve year old and not a mighty king of a thriving city. After an awkward silence Arthur made a decision.

"Very well Gaius, but have Merlin report to my chambers as soon as he's finished."

"I am here, you know," the man in question huffed from his position on the ground.

"Really? Because you looked like you were taking a nap," snapped the royal.

The warlock was about to protest, but he did feel a bit out of sorts and had only caught the last few words of conversation. Had he really drifted off?

"Are you alright, Merlin?" Gaius asked his ward, seeing that the young man looked a bit peaky.

"Tired," he offered with a feeble bob of the head.

"Well, see to it that you go to bed early and don't wait up for me," the physician turned to leave.

"Where are you going?"

"I have to check on Marion and the new babe in the lower town." He blustered; he'd already told his ward this information. "Don't forget to tidy up after you have finished," Gaius nodded to the king and bid farewell, making his way toward the gates of the citadel.

The warlock let his head flop back down and listened to the retreating steps of his guardian. He really did not want to get up, however that choice was not available. He felt a nudge to his calf and squinting through his fingers he saw Arthur eying him expectantly, hands on hips, frown on face.

"Are you going to lie there all day?"

Merlin blinked a few times and struggled to his feet using the royal's outstretched arm as a support. Once he was standing it took a moment for the two kings to merge into one.

"There is no shame in losing to the finest swordsman in Camelot," Arthur quipped.

"I could have beaten you easily if I'd wanted to," the sorcerer sulked.

"Yes, of course you could," the king said sarcastically. The potion's not working yet – perhaps it's faulty?

Merlin let out a large yawn.

"Oh, am I keeping you awake? What was it you were doing last night Merlin?" Arthur could not contain himself; the lie had been bugging him all day.

"I was mending the wall in the lower corridor," the warlock found himself saying.

"What? In the middle of the night?" Arthur screeched, searching the skies.

"Well I could hardly do it during the day, could I?" the servant responded sticking his bottom lip out like a petulant child.

Arthur threw his hands in the air; he struggled to find the words. "I despair of you! You are without a doubt the strangest man I have ever met," he snorted. "Don't be late this evening," and with that he stormed off, leaving the warlock feeling dazed and confused.

Merlin had just been about to explain that one of the wards he'd placed on the castle wall had backfired, causing the sizeable hole in the masonry which had taken him all night to fix. Thankfully Arthur had left - he could not believe he'd been about to say something so incriminating. It must be the sleep deprivation; he felt terrible.

As the sorcerer hobbled towards the castle he murmured a spell to take away the pain in his leg, not caring if anyone saw him. He felt absolutely wretched. At this rate he'd never get to be an old man like Gaius, excessive chores and his job as secret defender to the king would kill him young. Evidence was plentiful for such a claim; there weren't many old servants – but then, there were even fewer old kings – as soon as a monarch becomes vulnerable the opposition takes advantage. Merlin stifled those macabre thoughts; he was not going to let that happen to Arthur.

Little did he know his own life was now in danger, and from the very man he had sworn to protect. Arthur had given him a potion which -unbeknownst to the king - had festered, changed, and mutated over the last three months. No longer was it just a truth tonic, but a deadly poison.

Fate had finally given the warlock his wish; he was completely oblivious to his perilous predicament. A lethal toxin was currently being pumped around his body with every beat of his heart. Even if he had known, it was too late to act.

So, did anyone see that coming?

In the next chapter, our boys have their talk whilst Merlin is under the influence - I've been itching to get to this part since the beginning and hope you will enjoy it too!