There was a case, a rather establishing one at that, and Sherlock was worn from head to toe. Exhaustion constantly gripped ahold of his wrists and ankles, pulling him into a standing slumber, but being who he was and with the brain he had the shaggy violinist stuttered awake each time.
John watched all this with a hidden smirk and a sly chuckle.
He was tired too. His head was a mess with fingerprinting and DNA coding and maps of London and ingredients in types of quiches. It all spun around in that soldier's mind and was now (partially) useless – the case was over…through and through.
Sherlock held open the door to 221B with a shaky hand while John mumbled a scratchy "Ta," towards the violinist's direction.
They shrugged off their coats with impatient sighs and traveled somewhat towards the kitchen. John absentmindedly began the process of making tea. Sherlock disappeared into their room.
He returned seconds after John had placed their mugs on the table wearing his sapphire dressing gown. The doctor nodded in regards to the detective's change of clothing whereas the detective stumbled to keep his eyes open. What time was it again? And how long had they been up? Sherlock more hours than John, obviously, but both were exhausted out of their wits.
The sipped and slurped at their drinks (whatever would please them) in a thick moment of silence. Their actions were simultaneously rhythmic, as were their deep breathing. Almost one time or the other Sherlock would find John (or vice-versa) in the process of falling asleep and would be forced to nudge him conscious. It was a steady pattern of an engaging case night for them. It was normal.
When John finished with his tea, he stood up - a large scrape of lumber against lumber from the chair sliding alongside the floor - and shuffled to place his mug in the sink with the rest of their dirty dishes piled sky-high. That was normal too.
But John changed the plans.
Exhaustion did that to him sometimes.
He hobbled to where Sherlock was seated, cupped his fingertips along Sherlock's jaw, kissed him on the forehead, and then went to bed. He didn't care if Sherlock thought the action was stupid, sentimental, or any other adjective he fancied. He was just glad they finished the case successfully.
Once John had shut the door to their room, Sherlock smiled a large, sloppy grin.
Exhaustion did that to him sometimes.
And that was okay.