John felt helpless, sitting on the edge of his bed. Sherlock was spending the valuable hours they had so graciously been provided with by the bomber hunched over his microscope, trying to figure out what had killed Carl Powers. He'd told John he might as well get some sleep while he could. John couldn't. He didn't really want to disturb Sherlock while he was working, but just sitting there doing nothing wasn't an option either. He'd done enough of feeling useless.

'Sherlock?' he said, walking into the living room. Not taking his eyes off the microscope he was gazing into, Sherlock waved a hand at John in a dismissive manner, as if he wanted John to shut up. John sighed and sat down at the table, facing Sherlock.

'I want to help,' John said. 'You only have a couple of hours le-'

'Shh,' Sherlock interrupted, still focused on the microscope.

John made a face but shut up anyway. When Sherlock finally gazed at him after scribbling something down on a small piece of paper already filled with notes in his cramped but elegant hand, he looked almost thankful.

'What did you want to ask me?' Sherlock said, leaning back in his chair, his long legs stretched out under the table, brushing the legs of the chair John was sitting in.

'I want to help,' John repeated. 'Is there anything I can do?'

Sherlock pondered the question for a moment. 'No.' His expression didn't betray anything, but the tone in his voice made John realize Sherlock sounded regretful. It sounded as if he wanted John to help, but there simply wasn't anything he could do at this point. Then: 'You can talk to me. It helps me process.'

John looked up, surprised. He knew perfectly well Sherlock could figure everything out by himself, without John talking to him. Which meant this proposal was Sherlock's way of letting John know he wanted him to feel included. Touched by this gesture, John decided to play along.

'What do you want me to talk about?'

'Anything.'

'Okay, then tell me this.' John's mind had been returning to one thing over and over whilst he had been trying to fall asleep. 'That Jim guy, Molly's boyfriend.'

'Who is, in fact, gay.'

'Yes, that one. When you informed Molly of that particular issue, you said something about personal grooming habits.'

Sherlock nodded. 'And now you're wondering if I'm stalking you.'

'I- wait, what?' John frowned, once again baffled by the incredible, unfathomable way Sherlock's mind was always ahead of his.

With a small sigh that anybody else might've passed off as frustrated, Sherlock started explaining. 'You made clear you didn't believe my conclusion that Jim is gay because he maintains a certain level of personal grooming, based on the fact that you put product in your hair as well. Although I could've gone on and thereby conclude that both you and Jim must be gay, I reminded you of the fact that you only put product in your hair in order to wash it, as opposed to Jim, who clearly uses certain hair products to consciously style it. This particular remark made clear that I know your personal grooming habits, which may have lead you to conclude that I have thoroughly studied your every move and thereby gave you the idea that I might be stalking you.'

Sherlock only lifted his gaze after he had finished talking, meeting John's slightly widened eyes. Although he should've gotten used to Sherlock's deductive speech waterfalls, he still felt a little out of breath everytime he was there to witness one.

'So… What are you saying? That you haven't done any substantial research to the certain brands of shampoo I use? Is it one of my more ridiculous assumptions, lacking in logical reasoning?' John said in a feeble attempt to match Sherlock's usual turn of phrase.

'No,' Sherlock simply answered.

'What?'

Sherlock quite unceremoniously shoved the microscope out of the way, leaned forward, put his elbows on the table and pressed his fingers together. He peered at John over his joined fingers.

'No, that is not a ridiculous assumption, it doesn't lack in logical reasoning and I have, in fact, done some substantial research to the certain brands of shampoo you use.'

John's mouth involuntarily opened. 'Oh.' Sherlock never took his eyes off John at this point. 'So you are stalking me, then?'

'I suppose, in the strict sense of the word, I am. We barely leave each other's sight, and I have a habit of troubling you with all sorts of matters.'

'And you study my every move.'

'Well, not right now, obviously. But you do share an apartment with me.'

'Yes, I know,' John sighed, eyeing the science-related mess that was their living room. Oh, I do. Living together with Sherlock Holmes was a little different than your usual flatshare. Only a little.

'Does it bother you?' Sherlock asked, and John looked up at the change in Sherlock's voice. He sounded a little… was that insecurity John detected?

'No. No, it's fine,' John hastily answered after staring at Sherlock far longer than the social norm required. 'It's fine.'

'Good.'

'Good.'

Sherlock's legs brushed John's when the taller man crouched back over his microscope. John watched him work for a while. Just when he decided it would probably be better to let the consulting detective do his job in peace, Sherlock spoke, never looking up from his work.

'I need you to check exactly how much botulinum toxin needs to be diluted to be considered botox.'

Grabbing his laptop, John giggled softly. 'I sure hope that has nothing to do with your level of personal grooming.'

'It's for the case,' Sherlock answers automatically, but when John looked up from the computer screen he could see Sherlock smiling into his microscope.