That’s the season's deep truth. Sherlock’s "high-functioning sociopath" routine is a survival mechanism. Moriarty is what happens when there is no mechanism—just pure, unfiltered, gleeful destruction. John isn't Sherlock’s assistant. He’s his conscience . His tether. The one who asks, "Is it worth it?" when Sherlock forgets that victims are people.
The season’s primary focus is the blossoming, yet complex, partnership between (Benedict Cumberbatch) and Dr. John Watson (Martin Freeman). sherlock season 1