"Fucking hell, Sherlock—when did one smoke turn into a whole carton?" John tipped the empty box upside-down and tossed it onto the table again. He followed the detective's restless movements with his eyes as he paced up and down the living room, muttering to himself. "Sherlock?"

"I'm busy."

"Yeah, I can see you have been. What's all this?" He gestured to the photos and notes pinned to the wall, all different shots of the two murder victims Sherlock had so fiercely insisted were Moriarty's doing.

"This is work, obviously! I need to figure this out—I need to know why! It's staring me in the face, I know it is—but I can't see it!"

"You need to relax. We'll figure this out. Okay?"

Sherlock's dishevelled curls and wide, shadowed eyes, combined with his incessant pacing and muttering, only completed the image of a madman.

"Sherlock, listen to me. When was the last time you slept? Can you tell me that?"

He threw up his hands, glaring at the wall. "I don't know—I guess… kitchen floor."

"That was days ago. I'm surprised you're still coherent. Jesus… I know you want to solve this, but it's obviously going to take a while. You know you can't just stay awake until then."

"Why can't I? I can't work when I'm asleep! Anything could happen! Wasted time. What if I cut myself in my sleep?!" He ran a hand over his face roughly and turned on his heel to begin pacing again. "I'll lose control!"

"You're delirious. Fuck… I guess it's safe to assume you haven't eaten, then, either. At least I had you drink that tea last night…"

Sherlock wasn't listening. He was too busy staring intently at the photos, one after the other, mentally cataloguing every detail he could see. He stepped back, and wavered on his feet slightly before straightening his back and catching himself.

John sighed heavily. He'd have to try a different tactic. "Okay. Alright. So, you've been working on this for days, yeah?"

Sherlock turned to glance at him with an unspoken 'and?'

"Any leads?"

"I—I…" He swallowed. "It was Moriarty."

"Yeah, that's what we said the first time, remember? Have you figured out anything new like this, or are you just making yourself ill?"

"I'm fine…"

"But not okay?"

"Leave me alone, John! I need to get this out of the way! I need to focus!"

"At least change your clothes, then."

"There isn't time!" He was gesturing fervently with every word he spoke, as if to put on an even better demonstration of an energetic lunatic.

"You're mad…"

"I'M WORKING!"

John drew in a deep breath and let it out, moving over to the armchair and lowering himself into it. "Have you ever thought that maybe this is exactly what he wants? Moriarty. What if this is all to drive you crazy, to make you stress yourself out to the point of delirium? Make you less of a threat? Because if that's true then it's certainly working."

"What are you trying to say?!"

"Calm down. Let yourself rest. The case will still be here when you wake up, and nothing bad is going to happen in the meantime. Alright?"

Sherlock hesitated, but his gaze hadn't lost any of that intense fire. "I told you. I can't. I can't—I've tried. I can't sleep."

"Why not? Is there any particular reason, other than the case?"

"I don't know! All I know is I can't stop thinking—but I can't focus on the important thing! I can't focus on the case! I keep feeling, and it's distracting, and I can't turn it off!"

"You can't just turn your emotions off, Sherlock. That isn't the way they work."

"But that's what I need to do! They're in the way!"

John pinched the bridge of his nose. "You're not a machine. Quit acting like one. I really need you to be human right now."

...

Despite John's best efforts that evening and the next day, the cups of tea on the table eventually went cold and the plate of toast on offer wasn't even touched. It was abundantly clear that Sherlock hadn't had a moment of sleep that night, either, and it really wasn't helping things.

By the time John returned from work the next day the flat looked as if a hurricane had passed through it, and the detective's mood was just as stormy and erratic.

He paced back and forth across the living room floor, hardly noticing that he was scratching distractedly at his arms in the process.

"Sherlock." John set his bag down on the table and waited for the detective to register the sound of his voice. "Sherlock, you need to sleep."

"No."

"Please."

"I can't."

"Then at least sit down before you fall down, okay? I'm going to make you a cup of tea, and I really do want you to drink it this time." He watched him until Sherlock had grudgingly taken a seat on the sofa, and then went to the kitchen to start the tea.

Sherlock looked down at his hands with mild curiosity. "I'm shaking."

"That's because of the exhaustion and hunger. Here, drink this." John frowned as he pushed the cup toward him.

A flash of suspicion showed in the detective's eyes. "You put something in it, didn't you?"

"What? There's nothing in here but tea, I promise. Are you okay?"

"Of course I'm not okay! I can't figure this out!"

John took the opportunity to push the cup into his hand and manually wrap Sherlock's fingers around it. "Drink. It's going to be alright. And lower your voice, you'll upset Mrs. Hudson."

Sherlock looked down at it, and then up at him, and for a moment it looked like he might protest further, but then his shoulders slumped a little and he slowly sipped the tea.

"Good. Finish that, and then, if you can manage it, I'd really like you to eat something."

"But John, I'm on a case…"

"Doctor's orders. I know what I'm talking about. Trust me." John took a seat on the other end of the sofa and waited for him to finish the tea.

After a while Sherlock seemed to give up on it and set the cup on the coffee table, leaning back and curling up on the sofa. His long legs were almost on John's lap, though he did his best to stay on his side of the sofa.

"Is that any better?" John leaned over and picked up the mostly empty cup, but he didn't get any reply. "Sherlock?"

He glanced over at the detective's face, and let out a soft sigh of relief.

Sherlock's eyes were closed.

His features were finally relaxed.

His chest rose and fell slowly as he breathed.

Asleep.

Finally.

"You needed it, you big idiot…" John set the cup back down again and settled back. He wasn't about to risk waking him by getting up, and besides, all those nights he'd said he'd tried to sleep but couldn't, he'd been alone.

And here with John next to him he was out like a light.

It was probably presumptuous of him to think that he could have that much of an effect on Sherlock, but it certainly made him feel more needed, and that was always nice.

At some point Sherlock shifted and stretched out a bit, but John was determined not to mind.

Hopefully the detective would at least be a little easier to deal with once he was rested.

Maybe he'd even agree to eat something once he was a bit more rational.

John could only hope.