Sleep.
One simple word for a simple human necessity, and John desired it more than anything else right now. It had been a long day at surgery, and, as he half-stumbled up the stairs to the flat, the only thing that passed through his mind was that single, blissful word. The concerns of the rest of the day disappeared into the fatigue fogging his mind.
Mostly.
As John walked into the flat, he expected to be dragged into some convoluted scheme by his flatmate, who had been working nonstop for the last few days. For a man who often forgot to eat, sleep, or generally notice the comings and goings of anything around him that did not pertain directly to his work, Sherlock Holmes had his surprising moments of excitability. And, if the string of texts John had received throughout the day were any indication, Sherlock was in the middle of something very big, the nature of which he had naturally left out of his very one-sided conversation.
No, John feared there would be little sleep for him tonight. He braced himself, waiting for his flatmate to descend upon him and force him into helping with whatever scheme he had up his sleeve.
Yet this was not the case. Instead, John found Sherlock sprawled on the couch. At first, he thought that the consulting detective was lost in his thoughts. As he stepped closer, however, he realized that Sherlock was on his side, hair tousled and snoring softly. This sight was so unusual, in fact, that John was convinced his tired mind was playing a trick on him.
But it was not a trick. Sherlock was finally asleep.
A forgotten volume rested on the floor near Sherlock's limp hand. John knelt down to pick it up, and he found himself looking instead at the figure on the couch. Though he suspected his own drowsiness clouded his judgment, John concluded that, in his sleep, the consulting detective seemed almost childlike. When he was awake and in control of his emotions, Sherlock was cold and distant, above the world and above him. In his sleep, he had no such control; in his sleep, he was as human as anyone else. John smiled at the sight.
Coming out of his reverie, John picked up the book, and he set it on the table. Had he read the title of the book, he may have pieced together the source of Sherlock's excitement, but he barely noticed the object. Instead, he retrieved a blanket, and he draped it carefully over his friend. Sherlock stirred a bit, mumbling something about fingerprints, before settling back into his dream.
John lingered for another moment, absorbing the strange sight of a sleeping Sherlock, before slowly working his way upstairs. There would be plenty of time for fingerprints, suspects, and experiments.
For now, there was simply sleep.