At first, it was a broken wrist. It had happened during a chase, Sherlock had tumbled to the ground, rolled slightly, but seeing no obvious damage, got back up and managed to apprehend the suspect. It was only later that night at the flat, when Sherlock shrugged his coat off and absentmindedly went to roll up his sleeves to play the violin, that John grabbed at his arm.

"Sherlock," he gasped, "what the hell happened?"

Sherlock had the presence of mind to let out an 'ouch' and look entirely unimpressed after he saw what John was referring to. His wrist was swollen as well as turning interesting shades of blue and purple.

"Why didn't you tell me Sherlock?" But Sherlock really wasn't listening, he was examining the bruising pattern as well as the slightly off angle that he hadn't noticed when his jacket was on.

Broken, definitely.

"Come on," John insisted, pushing Sherlock towards the door, setting his coat over his shoulders.

"Stay here for a second." Sherlock watched as John leapt up the stairs to his room, dug around in his closet looking for something medical bag and bound down the stairs.

"Hold still and give me your arm."

Sherlock raised an eyebrow, wondering how he could possibly do both.

John rolled his eyes and Sherlock grudgingly held out his arm for John to splint it.

The cab ride to the hospital was spent in silence. Sherlock knew there would be no getting out of this one.

Before they had even left the flat, as he was splinting his wrist, John had muttered something about surgery and he would be lucky if that wasn't necessary and something about secrets and criminals and chases. Sherlock wasn't really listening. He was busy looking pained.

He thought he behaved rather well at the hospital. He protested a bit when John insisted on no pain meds, but really couldn't be bothered. He posed for all the x-rays with minimal conversation lucky for that x-ray tech and even bit back a response to the on call orthopaedic specialist, who commented that his wrist was indeed broken. REALLY? (Maybe he shouldn't have done that though, because now there was blood in his mouth. Drat.)

He was pleased when it was announced surgery wouldn't be needed, and then less pleased when it was determined he'd need a cast. Should have seen that one coming though, really.

He picked out a blue to match his scarf, and stayed awake without any pain meds while they fixed the displaced bone. Sherlock insisted John leave at this point, to call Lestrade and Mrs Hudson, but under no circumstances Mycroft. (He'd already know anyway.)

("Extremely high pain tolerance," he told the nurse when she looked at him funny as he watched without so much as blinking when the bone in his arm slid back into place. Sherlock doubted she believed him.)

But John didn't seem too suspicious of that incident, and Sherlock dutifully wore the cast, occasionally elevated it, and grudgingly agreed to no cases for a week.

The eighth day was an entirely different story.

John had been somewhat suspicious of Sherlock's behaviours ever since he had learned about the drug use. Any odd behaviour was not cause for concern in John's eyes.

And Sherlock had figured out that lack of pain was unusual to John. So while John complained about his aching shoulder after he had to tackle and wrestle a culprit to the ground, Sherlock chimed in with how sore his chin was from playing his violin so much. (Probably not the best one he'd come up with, but...)

He feigned headaches once in a while, mostly when he was entirely bored and perhaps even exhausted. John seemed to accept this, and just gave him some paracetamol and sent him off to bed.

When he was sick (evident by the fever that persisted and the swollen glands in his neck and the general exhaustion he felt) he claimed a sore throat when it appeared red in the mirror, and sore muscles any time his fever was over 38.5. It was a good system, and it worked. At least it did for a while.

The broken wrist and utter lack of reaction to it was the penultimate proof for John. What really clinched it was the fever and resulting seizure.

It was the eighth day after the broken wrist incident, meaning that Sherlock felt he was good to work again. (He felt good to work the other seven days too, but had worked out this schedule and convinced himself it would be for the best.)

It happened after a chase. It was a warm spring evening, and John was confounded that Sherlock was still wearing his coat and scarf while running around London.

Sherlock was special though, but just how special, John had no clue.

"Sherlock?"

"Hmm?"

"Are you feeling alright? You're looking rather... off," John pointed out, seeing his flushed cheeks and paler than usual face.

"Oh," Sherlock noted faintly, before he promptly passed out, leaving John clutching too few, and yet too many, kilos of consulting detective.

"Dammit," he said out loud after a moment.

It was doing to be another one of those nights.

This hypothesis was indeed confirmed, as Sherlock began to seize almost immediately after he uttered that statement, as if the detective was planning the entire thing. Wouldn't put it past him, he thought, then automatically felt guilty. Of course Sherlock wouldn't do that. Would he?

John shook his head. That wasn't what mattered right now. What mattered was the seizure.

John set him down gently on the floor, taking special care of his broken wrist, praying that the bone stayed in the right position, because if it moved this time, it would need surgery.

And it was as he was removing Sherlock's half off coat in the hopes that he wouldn't twist himself up in it that he realized the detective was burning up. Really.

So John pulled the coat off, and unbuttoned his shirt, but was most definitely not going to touch the pants. And John held his head and cushioned his arm and waited until the seizure subsided. The fever, John decided was the reason for the seizure. The reason for the fever? That he had no clue about.

Thankfully, his medical bag was still on the messy coffee table, and was within arm's reach. John fumbled to find the thermometer, and shoved it not so carefully into Sherlock's mouth, waiting until it beeped to glare at Sherlock.

41. No wonder.

"Why Sherlock?" John sighed. "Why?"

Sherlock did not respond. Of course.

"Sherlock!" He shouted, as if that may work. And it sort of did, because Sherlock stirred a bit.

"Sherlock," he repeated just as loudly. "What's wrong?"

Sherlock giggled before replying. (What John would give to have that on camera.)

"See Pa!" Sherlock sang. Or at least it sounded like that's what he sang. Could have been "Seep a [teabag?]"

John shook his head. In this feverish state, Sherlock could be telling his the chemical formula for his secret pepper spray and would never know it.

"Right," he told Sherlock. "Stay here. I'll go get a wet cloth."

Sherlock obeyed, sort of.

John returned with the cloth and wrapped it around Sherlock's neck.

Sherlock murmured. John took that opportunity to stick the thermometer back in Sherlock's mouth.

Dropping. And dropping quickly. Good.

He hoped that Sherlock would soon be lucid, mostly so he could explain what the hell was going on.

Sherlock was soon back to normal. Well, he says normal...

He seemed rather disinclined to tell John what that was all about, but John was not beyond sitting on his feet to prevent him from escaping.

So Sherlock relented, and sat there scowling as John debated how exactly to go about asking.

"You were muttering something like 'Seep a...' something. Steep a cup of tea?" John asked, glancing at Sherlock.

Sherlock grinned. "No, John, not at all. CIPA."

John looked at his blankly. "That's what I said."

Sherlock rolled his eyes. "No, you said 'seep a' as in s-e-e-p a, and I said CIPA as in capital c-i-p-a. Huge difference."

"CIPA," John repeated.

"There you go," Sherlock exclaimed, grinning. "Now you've got it!"

John rolled his eyes. "It's no different," he pointed out.

"It is..." Sherlock muttered. He shook his head. "Heard of it?"

"Of course I've heard of it Sherlock, I'm not stupid." John snapped.

Sherlock only smirked. "Just checking. It is rather rare," he noted, examining the cast on his wrist, no doubt wondering when he could cut it off himself.

John rolled his eyes. Of course it was.

"Well," John began slowly. Sherlock could practically hear the gears turning in his head, thinking, thinking, thinking... "That explains a lot."

Sherlock nodded. Yes, John. Yes it does. Oh look at him. All the pieces are clicking into place in his head and oh! there it all goes, making sense. See John? This is what it's like to be me.

"Huh," John commented, no doubt having reached the conclusion Sherlock assumed he would.

"The wrist... the broken ribs... being sick?" He shot a look at him. "How could you complain of a sore throat if you couldn't feel it."

Sherlock looked away. "Umm..."

John rolled his eyes. "That was a lie, wasn't it? And... the headaches too?" he demanded.

Sherlock looked at him sheepishly and shrugged.

"I imagine that's when I would have headaches," he informed John. "My head feels..." he frowned, looking for the right word, knowing that there really wasn't one. "Fuzzy. Full. "

John pondered that for a minute before asking a burning question.

"So... what's it like?"

Sherlock rolled his eyes. "That's a rather ridiculous question," he pointed out. "I have never not know what it is like, and therefore can't describe what it is like. It's like asking you to describe pain to me, or heat, or frostbite. It just can't happen."

John sat back thoughtfully.

"I could try," he insisted.

"Alright then," Sherlock replied, smirking. He knew how this would go. "Try."

"Well..." he began thoughtfully. "Frostbite is like... well, how I'd imagine it would feel to have an animal nibbling at your fingers and toes, because it's sort of tingly but not a nice tingly, a bad sort. It's like when your foot falls asleep, and then it starts feeling again, and it hurts. Although," John continued, seeing Sherlock's rather interesting expression, "I suppose you've never felt that either."

Sherlock shook his head, smirking slightly.

"Well. Moving on then. Heat is... it's like your body can't fit inside itself anymore and it doesn't want to have to touch your skin, so it tries to sweat itself out, because maybe it'll be able to slip out, except it's so uncomfortable, and you don't want to do anything or touch anything because that only makes it worse."

He looked at Sherlock. "Better?"

Sherlock rolled his eyes. "Barely."

John found this to mean 'yes', and continued. "And pain is..." he frowned, knowing this one would be the most difficult. "Pain is screaming and crying and tearing and burning at your flesh, all at once. Sometimes it gets so bad you want to die, because that would be better than spending any longer in pain." Sherlock noted the distant look in John's eyes, and knew that he was remembering. "And sometimes it comes and goes, throbbing, likes waves crashing on a shore, except you're the shore and you keep getting crushed by the tons of water until it finally just turns you into sand, because you can only resist it for so long. But sometimes it's more of a rushing river that keeps going and you're sure you'll drown because it never stops." His voice was wavering. "And the banks are steep stone, so there's no chance of getting a grip and climbing out, because it's impossible. And you know that there'll be rapids and bends and waterfalls and there's nothing you can do about it. You can try swimming against it, but that will just exhaust you and get you no where. All you can do is stay afloat and hope that someone will throw you a rope, or that you'll slip under for good."

Sherlock noted the blank look on John's face, and waited while John came back to the present.

"Do you get it now?" he asked quietly.

Sherlock paused for a moment, thinking about that.

John interpreted this silence as a 'no'.

"Fine," he muttered. "Not like I tried to explain it to you the best I could, even going so far as to tell you how much I hurt. But no, Sherlock Holmes can't feel anything."

Sherlock opened his mouth. "John," he began.

John barely let him finish the word before cutting him off, continuing on his tirade.

"That's what the drugs were about, isn't it?" John eyed him. "The drugs made you feel things. They made you feel great. Which is wonderful for you, really, because you can't feel pain. So you can't possibly understand how any of the rest of us could possibly be incapacitated by something so simple as our transport," he drew out sarcastically.

Sherlock fumed. Not true, not true, not true!

But John wasn't ready to listen to that.

"At least with the drugs I could feel something," he snapped.

John looked at him, rather shocked. Sherlock had never admitted anything like that to him. In fact, he didn't even mention the drugs. (John probably never would have found out if it weren't for the drugs bust. He and Mycroft would have just danced around it, Mycroft inferring to it and John being entirely clueless as to what the conversation was really about.)

"You can feel things without drugs, you know. Like happiness. Joy. Fulfilment."

"Sociopath," Sherlock reminded him.

John rolled his eyes. "We both know that's not true..." he muttered.

Sherlock spun around to face him.

"Do. Not. Quote. Him." Sherlock hissed.

John stared at him blankly.

"Fine. As long as you admit that you are not a sociopath." Sherlock opened his mouth to protest. "I'm not saying you have to say what you are, because you and I both know those words will not be spoken out loud," John rolled his eyes, "but you are not a sociopath."

He looked towards Sherlock expectantly.

"As you wish John," he scowled.

John decided that would be as good as it got, and left it alone for then.

"Anyway. Back to what I was saying. Drugs aren't the only way to feel things."

Sherlock looked towards him skeptically.

John rolled his eyes.

"You're not a sociopath, Sherlock. So deny as you may, you do have feelings." He stood up. "You may not be able to feel physical pain, but there will always be emotional pain."

Sherlock watched as John climbed up the stairs to his room, pondering that. Interesting...

Soon enough, Sherlock got to find out for himself.

And of course, John was right. Because while the fall off the building didn't hurt, even though it did break him, what really hurt was watching John at his grave.

He understood what John was describing then. The screaming, tearing, rushing river that he was trapped in somehow spilled out of him, no matter how hard he tried to prevent it.