A/N: A quick glimpse into the past of the Holmes men.
"I worry about him. Constantly."
Though Mycroft's sudden presence appeared to be random, both he and Sherlock were well aware that it was not. He planned every move precisely, and he followed that plan without fail. And just because Sherlock had grown accustomed to it didn't mean that he had necessarily come to welcome it.
They were both young; Sherlock twenty and Mycroft seven years his senior. In spite of their shared childhood (or, perhaps, because of it), the brothers pushed themselves constantly, forced themselves to succeed, to excel. For the elder Holmes, that meant creating a job for himself in the British Government. As for the younger...well, that was why Mycroft was here.
He worried about Sherlock. Constantly. His brother was brilliant, there was absolutely no doubt about it. No, it was the methods that he used to both dull and enhance his brilliance that were cause for concern. Sherlock had become quite fond of tobacco, and his occasional use of cocaine was steadily becoming more frequent. And Mycroft did not approve. Smoking, though a filthy habit, was the safest of his brother's vices. But Sherlock was extremely waif to begin with, and the cocaine was eating away, slowly, at his thin frame.
It would have been senseless to stop him. No matter how many men he had on his brother, Sherlock would always find a way to shake them off. There was always a way for him to get what he wanted. Mycroft understood; truly, he did. Sherlock needed a way to combat himself, to keep himself sane. And in some way, that was what the drugs did: they kept him well inside his head.
It was the most Mycroft could do to simply check in on him, to make sure that he ate and bathed on a semi-regular basis. That was all that Sherlock would allow him to do. And now, studying his brother, Mycroft wished that he could do more. He saw the bright fever of Sherlock's eyes, the way his cheekbones seemed to jut out of his gaunt face, his emaciated frame..He saw all of this, and he despised himself for it.
No words were exchanged as the brothers met each other's eyes. No words were said, but volumes were exchanged. With a steadying breath and a tight grip on his umbrella, Mycroft Holmes turned to go, leaving his brother alone until next time. He worried about him. Constantly.