Mycroft had always won at chess, but Sherlock had always won at Go. Mycroft used to think it ought to be the other way around, because chess, like Sherlock, was about piercing to the ultimate goal, of knocking over the king, while Go was about surrounding and dominating. But now he realized that it was right, because chess was essentially about humanity, and Go was essentially about black and white abstractions. Sherlock could reduce people to abstractions, while Mycroft dealt with what people really were inside.
Maybe someday Mycroft and Sherlock would play chess again. Maybe someday Sherlock would win.
Thus endeth "Conscience."
"Vulcan" (http:/www . fanfiction . net/s/6560821/1/Vulcan) completes the series.