"Sherlock," John began, two days after the serial killer incident.
Sherlock was sprawling on the couch, bemoaning how his violin playing ability was affected by the stupid bandage John made him wear on his wrist.
He paused for a moment.
"What," he said flatly.
"How did you determine that was what you had? Like, for a sure diagnosis."
Sherlock sighed, knowing John wouldn't like his answer.
"An EEG. And an MRI. Andaspinaltap."
He mumbled the last words, pushing them together.
John still heard.
"You mean, you went to a hospital willingly to get a spinal tap done, and didn't even insist I come or do it. Not to mention that I didn't hear about it from any of the doctors at..." he trailed off, noticing Sherlock's disapproving look that usually meant he was wrong.
"Okay, so you didn't go to the hospital. And you can't do it yourself. At least you shouldn't be able to." He looked at Sherlock, who shook his head. Relieved, John continues. "Alright. So then how did you do it? Blackmail someone?" John was joking, but his smile fell as he noticed Sherlock didn't deny that.
"Hang on, you didn't actually blackmail someone, did you?"
"Not really," Sherlock admitted. "Molly."
John looked shocked.
"I talked her through it."
"You're an idiot."
Sherlock nodded.
John burst out laughing.
Sherlock looked shocked. This was hardly a laughing matter.
"You, are a bloody idiot," he choked out while practically rolling out of his chair.
Sherlock smiled. He didn't disagree.
When John finished laughing, Sherlock shared some more information, which he found fascinating. John probably not so much.
"You know the only definitive diagnosis is through brain biopsy."
John stared at him.
Sherlock rolled his eyes. "No, I didn't do that yet. You can after, if you'd like."
John paled.
"Don't," he said shortly. "Just, don't." Sherlock began to open his mouth and John cut him off. "Not yet. I can't talk about it yet."
"Let me know when," Sherlock said, nodding slowly.
It wasn't the next day.
"No," John said the next morning.
"I didn't say anything!" Sherlock protested.
"I could feel you staring at me," John replied, spinning around and pointing a finger at him.
Sherlock was silent for a second.
"We can talk about who we're going to tell and when we're going to tell them."
"Oh," Sherlock said. "Do we have to?"
John rolled his eyes.
"D'you know how dense you can be some times?"
Sherlock grinned.
"Enlighten me."
"Of course we have to tell them. Just cause they're not the world's only consulting detective doesn't mean they will not notice anything. I'm pretty sure Lestrade already found it suspicious that you fell over a kerb."
"I blamed Anderson. He was standing nearby."
John snorted. "I bet he believed that."
"Of course he did," Sherlock replied with an entirely straight face. "Anderson's face does that to people."
There was a beat until they both burst out laughing.
"It does make me feel a bit special you know," Sherlock said out of the blue one day. John only looked at him, confused. Sherlock rolled his eyes. "This disease. It's rare. And the type that I have, sporadic, is most common with people in their 60s. Cases in people below 50 are rare. It's just fitting, that's all," he remarked bitterly.
John wasn't sure how to respond.
"And if I have seizures that's even more uncommon. Rare cubed! Takes notes please John."
John winced.
Sherlock rolled his eyes again. "We are going to have to talk about this. Soon."
John nodded. "Just not yet."