A/N: A perfect match to the symptoms shown in the episode would've been mountain laurel poisoning, but apparently that only grows in the States (or, more accurately, is native to the Eastern U.S.) so it was more than a bit unreasonable for Morgana to have it, magic or no.
Oh well, this is also fun- and allowed me to add in a few things (mwahahaha).

Anyway, I've put up a poll in my profile so if you'd like to have a say in what I write next please head on over there and vote :)

Now back to our hero!

Merlin woke when two spots of warmth appeared on his shoulders.
Feels nice...

But then his body informed him of the poison's continued effects.

Pure agony, simultaneously freezing and burning, seemed to be flowing through his veins instead of blood and he barely had any sense of his body apart from from it- for instance, that sharp white pain was his upper leg while the jagged throbbing was his head.

He would have screamed if he could, but found that his throat was nearly swollen shut and his jaw stubbornly refused to move.
In fact, he couldn't move anything, a problem that became even more distressing when he recognized the voices speaking somewhere near him.

Arthur... Gwaine...

They sounded so worried! He wanted to look at them, see what was going on, let them know he was alright- though that was patently untrue.

It was so cold. What had happened to the warmth on his shoulders and chest?
They were gone far too quickly. Of course, there were still the flames in his stomach, throat, and mouth.

He heard Daegal then, and Gaius; Arthur snapping out orders.
Reveling in the momentary presence of heat on his face, the dying man could have cried when he heard a fire was going to be built.

Something rough scraped against the inside of his cheek, bursting several of the sores that had formed there and agitating the acid burns- he could've cried for an entirely different reason at that point.

Then suddenly there was light and a blur of colors, the new stimuli almost enough to overwhelm his beleaguered mind.
Merlin wanted to look toward Gaius, but couldn't quite see where the physician was past the haze and the dark edges encroaching on his vision.

The heat was gone from his cheeks and the servant struggled to keep his eye open with his own power, sinking further into despair as his eyelid fell regardless.
No! I don't want to be left in the dark! Gaius, Arthur, Gwaine- help me!

He struggled to produce speech- any kind of sound, really, but only succeeded in inciting another coughing fit.
The sudden burst of air forced his frozen lips partway open but he knew it wouldn't be enough to prevent him from drowning in the blood that was coming up.

Then he felt warmth and pressure on his chest, back, and head; catching snatches of conversation as his body was shifted- his friends oblivious to the excruciating pain they were causing.

His stomach heaved, but his throat was too far closed to allow anything more to pass.
Merlin began to panic as he realized he wasn't getting any air and he redoubled his efforts to move- an arm, a hand, a finger even.
Anything... please, move...

His consciousness was slipping, and he was beginning to think it might be a welcome relief.

Without warning something forced its way into his mouth, aggravating the sores further as it reached back to brush against his swollen flesh, triggering his gag reflex and sending another wave of pain and nausea through him.

He could hear Gaius shouting now and the whatever-it-was disappeared from his mouth.
Small comfort.

Something hot and wet settled around his neck and he smelled the tang of vinegar along with gentian and something else he couldn't identify.
His throat loosened and Merlin felt the blood and sick rush into and out of his mouth, not even tasting it due to the state of his tongue.

Fingers poked around inside his mouth (he was reasonably certain it was fingers this time) then the digits were retracted and a cloth inserted, scrubbing the raw tissue and removing the residual vomit.

He could hear Gaius speaking in soothing tones- trying to reassure him that everything was alright, apologizing for causing hurt, saying it was necessary to help him- the words all but meaningless to Merlin who wanted to curl up and weep; a recourse that was denied him by his unresponsive body.

His ears became vaguely aware of a strained, high-pitched keening and he wondered for a moment where it was coming from before the increasing soreness of his throat caused him to conclude he was making the sound. Feeling his airway begin to constrict once more he forced himself to stop, the weak wail ending as a whimper before silence fell again.

Someone was speaking to him- his guardian, asking if he was awake.
Merlin squeaked in response.

He sensed hands on his face again, finger-pads against his eyelids, but although he was fairly confident he felt the lids raise the darkness remained.

Gaius' voice again, asking if he could see what was in the physician's hand.
Merlin looked around wildly, desperate to catch a glimpse of light and color but failing utterly.

I've gone blind...
Bitterness crept into his mental tone.
But then again, what does it matter when I'm dying?

The warlock almost wished he would just hurry up and get it over with.