I needed a bit of a break from zombie-Sherlock stories, so we'll go with mad scientists, instead. :) It was this or ghosts, but I may still do that later. This will probably be a two or three shot. Title means: 'From Science, Truth.' Based off a LJ prompt.

"Hiding from Mary again?"

John lurched back at the voice, catching his head on the wooden overhang he'd been tinkering with. The good doctor rubbed his smarting head, ignoring the knowing smirk from the man outside his shop door.

"Can I help you, Sherlock?" John griped. He only had so much time before his first appointment of the day, if the wick of his candle was correct. It wasn't that he didn't want to talk to Sherlock. In fact, that would be he exact opposite of his rationale. He didn't want to be late because they'd gotten caught up brainstorming. Again. "And I'm not hiding from Mary," he added, as an afterthought.

Sherlock gave him a thin, sideways grin. "Nothing that should take too much of your time, doctor. It would just appear that I have left one of my tools in your possession that I am in need of."

John thought back to the corkscrew looking mechanism he'd left on his work table. The last time Sherlock had been in his shop, showing John a new device he'd made to increase lung capacity and reduce triggers on people with asthma, he'd left it. John had no idea what it could be used for and thought about returning it himself, but he knew Sherlock would come back for it. Because he'd left it there on purpose, to give him a reason to stop by. John didn't see a reason he should stop. He went over to retrieve it.

"You know, you don't have to 'forget you tools' every time you want to pop in for a chat." John smiled at him jovially. "Not a crime to want to talk to someone just because you enjoy it."

Sherlock grimaced at him again and leaned against the doorjamb. "I admit to having and ulterior motive for my visit today. You see, I've come close to finishing my latest project and I wish for you to aid me further in its completion. Then again, if you had been able to assist me since the beginning—"

John rose his hand. "Now, you know I couldn't. I enjoy being your assistant, you know I do, but I am getting married next month." He smiled. "I wouldn't be a very good husband if I spent more time helping your plans than doting on her."

Sherlock frowned deeply. "You enjoy your time spent with me more than your time spent with her. You're better as my assistant. It's more exciting." His eyes narrowed.

"Sherlock—"

The scientist waved away John's half-hearted response. "Irrelevant. The past cannot be changed. By the end of the week, the machine will be finished and I will need to test it. Why don't you and Mary come? That way you don't have to feel guilty for dividing your attentions between the two of us, and I get my assistant."

John hummed. "What is your machine? Is it dangerous?"

"Not anymore," he replied. That really didn't make John feel any better. "I've found that correct frequency so as not to burn any skin." His eyes turned dreamy. "More experimentation may be necessary in regards to the brain's interpretation of pain and pleasure, however. I may have let the electrode run for longer than I should have." He turned, and John balked at the burn at the base of Sherlock's scalp. It was mostly hidden beneath his black fringe, but was glaringly obvious in contrast to his pale flesh.

"For God's sake, you're going to seriously injure yourself! Let me have a look at that."

Sherlock batted his hands away. "I've taken care of it, John. It is not my first or even most horrific injury attained while conducting an experiment. And it is hardly going to be my last."

"Shocking," John deadpanned.

Sherlock wrinkled his nose in distaste. "That is a horrible pun."

John's smile cracked wide. "I couldn't help it." Sherlock's glare meant he didn't believe him, but it was too warm for John to take to heart. "But yes, me and Mary will be there given I don't have any appointments. Is it going to be your usual spectacle?"

Sherlock heaved a heavy sigh. "The crowd seems to follow whether I want them to or not, so yes."

John chuckled. "You love the attention; don't even try to deny it." He mussed the scientist's hair fondly, to which Sherlock gave an indignant squawk. "Just try not to hurt yourself too badly. I don't want to stitch you back together so soon after the last time." He finally handed over the scientist's tool, and Sherlock held him there, eyes deep.

"It's good, then, that I have such a good physician to look after me," he said, voice sincere.

John gave him a twitchy sort of smile that probably easily portrayed the flutter in his stomach.

"Right. Um, I look forward to seeing the machine when it's all done."

The corner of Sherlock's mouth ticked. "As do I, John. I shall see you and Mary then." He bowed his head and retreated from the shop door. "Good evening," he followed with his exit. John took a deep breath.

Aftereffect of being in the presence of a genius, he supposed. From time to time you just get a bit too taken in.

It wasn't until he was on his way home that night, however, that he realized he still didn't know exactly what Sherlock's machine did.

"Mary? I'm home," called John. He removed his shoes at the door and hung his coat on the stand. His stomach still felt fluttery even though so much time had passed since his conversation with Sherlock. Perhaps he was more nervous about approaching Mary than he'd thought. She wasn't going to be happy about John just agreeing to Sherlock's demands, as he often did. If he was perfectly honest with himself, he knew it was ridiculous how often he humoured Sherlock's fancy, and yet he did anyway.

Well, if she was entirely against it, he would just have to decline Sherlock's invitation. And though the thought of not being there for Sherlock's display of genius made a leaden weight settle in his gut, he had to have priorities. And since he was Mary's fiancé, she came first.

Because he loved her, he told himself.

"Hello John. I'm making dinner, now. Come join me in the kitchen."

He did so, meeting her at the counter where she was cutting vegetables. She gave him a pleasant smile and he gave her a peck on the cheek. It was all very domestic.

Boring! said the Sherlock in John's mind, but he pushed it aside.

"How were your patients today? You're home a bit later than usual."

"You know I don't like to discuss the particulars, but everyone seems to be doing well. You remember little Molly? Poor thing had such a hard time with her back, but Sherlock's contraption had helped her immensely. She's standing much taller now, though that didn't help much with the nervous ticks." He smiled. "Think she's developed a bit of a crush on him."

"She's not the only one," Mary murmured, almost drowned out at the ferocity of the cuts she was making.

"What do you mean?" John hedged.

"Nothing. Just seems a bit unfair to be involved in a man so self-absorbed."

"It's just his way. He's brilliant; he just gets lost in his own head and forgets that he needs to act human every now and then."

"Is that what you do, John? Remind him to be human?"

He awkwardly shifted his weight. "Sometimes."

She let her gaze linger uncomfortably long. She was observing, and it made John anxious. He didn't see what she could glean that he didn't already know. But that may have been the problem.

"Sometimes I wonder how you can be around him so often," Mary continued, dragging more carrots into place. "I swear I would lose my mind. I can barely keep up with him when he makes his presentations."

"Speaking of—"

Mary dropped her knife on the cutting board with a clatter and braced her hands on the counter.

"Of course, he has something new, doesn't he?" She sighed. "What is it this time?"

"I'm not entirely sure, to be honest. I, er, wasn't helping with this one like I usually do."

"Sorry for the inconvenience," she snapped. That one stung quite a bit.

"Mary—"

"No, it's fine. I understand it means a lot to you." She shook her head. "Maybe someday I'll mean just as much."

"You know I think the world of you, Mary. Don't ever think otherwise," he tried to amend. Still, the words seemed a bit hollow, even to his own ears.

Mary didn't reply to that, but her resumed cropping slowed and she turned thoughtful. "And how much did you make today?"

God, not this again. John understood that Mary didn't come from a very wealthy family; he didn't either. But her constant vigil on their finances perturbed him. "Fair," he said. He didn't want to mention the little girl with a broken arm and two cents to her name, nor the elderly couple swimming in debts and poor health: both of which he'd cared for today and not charged a penny. Mary would be furious. He couldn't bring himself to feel guilty for her sake. "Sherlock's inventions have been helping a lot of people, so there have been less accidents. It's a good thing to not have a busy day."

"Have you ever thought that maybe you should charge for all you use his gadgets? These people are taking advantage of your charity, John. We can't be expected to live off good intentions."

"I make enough to not have to do that," he argued. "We are secure, love. We don't need to worry about it." He brushed her hair away from her dark eyes in a soothing gesture, but she crooked away from his touch.

"I need to finish dinner. I'll call you when it's ready."

"Yes, alright." He'd had enough arguing, but he needed to clear. "So about his presentation..."

"Fine." Mary retook the blade and began to slice. "But John, once we're married I want this to stop. You're mine, not his." A heavy chop. "And I love you."

Even though she said this, John felt distant and cold. There was no warmth in that phrase. Not like when he was doing something he loved.

Not like when he was with Sherlock.

He retreated from the room without returning the sentiment.