Admittedly, it hadn't been one of Sherlock's brightest plans, but assuming John was still mad at him (which was rather likely given the circumstances and the way things had been left last night) and even if John wasn't still mad at him, there was no way he would have permitted this.
Besides, the experiment wouldn't be successful if the subject knew they were being experimented on.

"What's this?" John asked suspiciously, as Sherlock held a cup out to him.
"Coffee. I made coffee."
"You never make coffee." Was this about last night, because really...
"I just did. Don't you want it?" Sherlock held it out expectantly.
"You don't have to keep apologizing," John told him, but Sherlock wasn't backing down. John took the cup from him."Thanks." He took a sip and frowned. "Mm. I don't take sugar..." Oh god he was giving him that look... where did he even get that look? John took another sip, trying to smile."That's nice. That's good."

Sherlock was appeased and turned away for a moment, interested in the conversation between Lestrade and the hotel owners.

John managed a few more sips. He really didn't like sugar in his coffee. Or his tea.

He drank just enough so that when he put the cup down, Sherlock looked like a puppy that had brought a chewed up slipper to his owner rather than a puppy who had been kicked.

John managed a smile.

"You know he's actually pleased you're here? Secretly pleased," John informed Lestrade as they left together.
"Is he? That's nice. I suppose he likes having all the same faces back together. Appeals to his ... his ..."
"Asperger's?" Oh man Sherlock would kill him if he knew he'd told Greg, even if he just took it as a joke... oh damn there he was. John held his breath.
"So, you believe him about having the dog destroyed?" Lestrade asked Sherlock.

Sherlock who was showing no signs of having heard John, replied "No reason not to."
"Well, hopefully there's no harm done. Not quite sure what I'd charge him with anyway. I'll have a word with the local Force. Right, that's that, then. Catch you later. I'm enjoying this! It's nice to get London out of your lungs!" Greg seemed rather chipper, John noted.

He wasn't sure why that bothered him so much, but it did. Perhaps it was the ache that had begun in his head.

He blamed Sherlock for that.

"So that was their dog that people saw out on the moor?" John asked Sherlock as Greg walked away, not wanting to be entirely left out of the loop.
"Looks like it," he replied.
"But that wasn't what you saw. That wasn't just an ordinary dog."
"No. It was immense, had burning red eyes and it was glowing, John. Its whole body was glowing. I've got a theory but I need to get back into Baskerville to test it."
"How? Can't pull off the ID trick again." This was far too much thinking this early. What is wrong with him? Sherlock usually didn't irritate him this much. John sighed, loudly.
"Might not have to. Hello, brother dear. How are you?"

John rolled his eyes. Was Mycroft going to buy that one. Really? John rolled his eyes again.

Sherlock noticed that John was somewhat sullen on the drive to Baskerville. He chalked it up to remaining anger from the night before, as well as some sleep deprivation. And perhaps the coffee. Sherlock frowned. But not the drugs. Shouldn't be the drugs; at least, not yet.

He shook his head and turned his full attention back to the road. He rather despised driving.

John felt Sherlock examining him, deducing him, but didn't really care. He was itchy. And hot. And rather irritable. And his head was still aching and he was beginning to get a cough.

That would be just his luck, to come down with something because he was out in the woods last night traipsing around looking for some mutant dog.

Like Sherlock would say, dull dull dull...

And now, to top it all off, there was an irritating wheezing noise that was getting increasingly louder and on top of that, he was getting dizzy.

Oh. Oh...Well. That was interesting.

John was audibly wheezing now. "Sherlock," he croaked.

Sherlock glanced at him and did a double take before pulling over.

"John," he said urgently, undoing his seat belt so he could get a closer look. "John, what's wrong?"

John rolled his eyes. Leave it to Sherlock to only bother asking questions when he wasn't capable of answering them. He glared at him. Sherlock seemed to understand.

Sherlock did a once over of John. Wheezing, rapid breathing, increased heart rate, rash (no, hives), and a flushed face. Sherlock would also predict that John's blood pressure was falling.

He snapped back to reality when John spoke to him again. "Bag," he growled, "bag," he repeated, gesturing towards the backseat.

Sherlock dove over the seat and resurfaced a second later with John's medical bag.

"Pen," John wheezed at him, and Sherlock shushed him.

"Save your breath. I know what I'm doing," he informed John testily. John raised an eyebrow, but conceded and closed his eyes. He kept breathing.

Sherlock dug through the bag before finding what he was looking for.

He fumbled with the pen, tipping it out of its case, cursing him suddenly clumsy fingers. He skimmed the instructions, knowing that every second he wasted John was sitting there losing oxygen from all of his cells and he pulled the blue cap off and jammed it into John's leg, silently apologizing for the pain.

He held it for ten seconds, just like he was supposed to. Sherlock pulled the needle out and tossed it haphazardly to the side, moving on to rub John's leg just like he was supposed to.

John groaned, but his breathing was growing clearer and the wheezes were not as audible.

"John," Sherlock asked anxiously, "are you alright?"

Of course he's not all right (idiot) he was just in anaphylactic shock.

"Are you better?" he corrected.

John nodded, still rather occupied with breathing.

An aspirin allergy was rather easy to avoid. Just don't take aspirin.

So John was entirely surprised, almost to the point where he didn't recognize the symptoms, to be going into anaphylactic shock now.

Typical, really.

Just another day in the life with Sherlock Holmes.

Sherlock had done well, injecting John and was now watching him with bated breath.

"M'fine," John muttered at Sherlock, suddenly exhausted despite the newly injected adrenaline coursing through his body.

Sherlock scoured his brain, looking for anything that related to allergies or anaphylactic shock. There really was only the information that he just read on the epipen that was clear right now.

Where did it go... Sherlock peered around the floor of the car and spotted it. He skimmed the instructions slightly more carefully this time.

"Right," Sherlock announced when he had finished. "Hospital. So put your seat belt back on."

John cracked open an eye.

"I never took my seat belt off," he pointed out.

Sherlock glanced down at John's lap, then his own. "True enough," he replied.

"And," John continued, "we're not going to the hospital. We've got a giant dog to catch."

Sherlock frowned. "The instructions on the pen said-"

"Sherlock," John interrupted with a half smile. (Sherlock was becoming suspicious of that smile.) "I'm a doctor. It'll be okay. And besides," he added, "a military base is just about as good as a hospital."

Sherlock frowned.

He did want to go back to Baskerville and get the whole case over with, but not if it meant risking John's health.

Seeing his hesitation, John added gently "I am fine Sherlock. Really. I haven't had an attack in ages." He frowned. "I actually can't remember the last time."

Sherlock hummed and hawed for a moment, but relented, just like they both knew he would.

"Fine," he announced. "But any signs of a second allergic reaction and you're going straight to the hospital."

John nodded with that same half grin again.

Sherlock decided he wouldn't go through with that experiment after all.

"Can you walk?" Sherlock asked him, still worried, when they arrived.
"'Course I can walk," John told him, rolling his eyes. Not a complete invalid thank you Sherlock.
Sherlock scrutinized him, but probably didn't think it was worth the trouble. He had other things on his mind.

Like waltzing right into Dr Stapleton's lab and demanding to use her microscope.

John sat down on one of the stools, still feeling rather unwell. He hoped Sherlock wouldn't take that long. He wanted to go back to the flat, to Baker street, and disbarring that, at least to his hotel room.

He was busy thinking about Mrs Hudson's tea when his thoughts were interrupted.
"Are you sure you're okay? You look very peaky." Dr Stapleton was indeed observant. John didn't feel so great still, and likely didn't look all that great.
"No, I'm all right," he said, halfheartedly.

She frowned a little bit at him, but then Sherlock threw his hands down and that was that.

Then there was the mind palace, which meant they got kicked out of the room and sent to another.

She scrutinized him again, and there was no Sherlock to rescue him this time. At least, not yet. John glanced at the clock and begged it to move faster.

"You're really not looking well," she noted.

John rolled hsi eyes. Damn her for being too observant.

"Well..." he trailed off. May as well tell her the truth. "I'm not feeling a hundred percent."

"Coming down with something?" she asked, going into mothering mode, reaching a hand out to feel his forehead.

She hesitated when her hand was resting on his forehead. It was nice and cool, John noted.

"Sorry," she said.

"Oh no, it's alright," he assured her. "I'm a doctor too, remember? That's my first instinct when I see someone who's not well."

"Mother," she added, smiling shyly at him.

"You are a bit warm though," he noted. "And red and... rashy." She frowned, pausing at John's neck and pushing his collar aside slightly. "Have you been out in the woods? There's poison ivy out there and sometimes-"

"No, no." John told her. "Nothing like that."

"What then?" she looked mildly interested.

John sighed. "Erm... allergic reaction. It's all good though," he added. "I had a shot," he informed her, rubbing his leg absentmindedly.

"When?" she asked curiously.

"On the way here." John froze, recognizing that really wasn't the right thing to say, because Dr Stapleton, being both a doctor and a mother, would insist he go to the hospital.

"Don't do that," he warned as she opened her mouth to protest. "I'll be alright," he reassured her, just as Sherlock burst in the room.

"Hound!" he cried.

It was all going well, they had solved it and knew who the culprit was, and John was thinking that maybe he was going to get a full night's sleep when he received the call from Henry's therapist.

Drat.

John wasn't in any mood to be running around in the forest after the little incident earlier that day, and really wasn't in the mood to be threatened by a dog hopped up on experimental drugs.

A small bit of him was glad that Frankland blew up. It made the chase a bit easier. He knew it wasn't right, but he was exhausted and it meant he could return to the hotel and collapse, sleeping for eight solid hours.

The next morning at breakfast, John was still pondering how he'd had an anaphylactic reaction when he hadn't ingested any aspirin or aspirin products.

But then when Sherlock appeared, muttering about the drug and the experiment and the case in general, it dawned on him.

"Hang on: you thought it was in the sugar. You were convinced it was in the sugar."
"Better get going, actually. There's a train that leaves in half an hour, so if you want ..." Sherlock stalled, hoping John would get distracted.
"Oh God. It was you. You drugged my coffee." John pointed his fork at Sherlock, who winced visibly as he said this.
"I had to. It was an experiment," he hedged.
" An experiment?!" John sounded furious and raised his voice to an uncomfortable decibel level.
"Shhh," Sherlock hushed, glancing around at all the other people. The one man... Gary?... was looking at them with a smirk. Sherlock glared at him until he looked away.
"I was could have died Sherlock. Actually died," John hissed, only slightly more quietly.

"Well, I knew what effect it had had on a superior mind, so I needed to try it on an average one. You know what I mean," he added, seeing the look on John's face at being called an 'average' mind.
"But it wasn't in the sugar."
"No, well, I wasn't to know you'd already been exposed to the gas."
"So you got it wrong."
"No," Sherlock insisted.
"Mmm. You were wrong. It wasn't in the sugar. You got it wrong." Sherlock noted darkly that John seemed rather pleased with that.
"A bit. It won't happen again." Sherlock attempted to smile at John. It was ineffective.

"And to top it all off, there happened to be aspirin or the likein the sugar which caused me to have an allergic reaction. Nice going on that one by the way," John muttered.

Sherlock rolled his eyes. "How was I supposed to know?" he demanded.

John stared at him, incredulous. "I've told you! More than once in fact!" He shook his head. "Don't tell me you deleted that!"

Sherlock blinked.

"Right," John said, turning back to his breakfast. "Right."

"Sorry," Sherlock offered.

John shrugged slightly.

"Really," Sherlock pleaded. "I'm really sorry."

John rolled his eyes.

"That's enough already."

Sherlock perked up.

"So you're not mad."

John shook his head slowly, and chewed and swallowed before responding. "I didn't say that," he pointed out.

"Oh," Sherlock's face fell.

"Although," John began to say, not even bothering to finish chewing before speaking, probably to prevent Sherlock from leaving, as he had just stood up and stretched, "I am curious as to how you are so good with an epipen."

John raised an eyebrow.

Sherlock looked away. "Erm..." he began, "well..."

He trailed off, obviously not wanting to share. He looked back at John and shrugged.

John rolled his eyes, but finished off the last few bites of his plate.

"Come on," he said, standing up. "We can discuss this on the nice, long, train ride back home."

Sherlock held in his groan, but John knew it was there.

Sherlock was not looking forward to informing John about the experiment with the oranges.