When the BBC's Sherlock debuted in summer 2010—and appeared in the U.S. on PBS a few months later—no one knew it would become an international phenomenon. The series has since gathered a diverse and enthusiastic fandom.

Like their hero, Sherlock fans scrutinize clues about the show's deeper meaning, as well as happenings off screen. They postulate theories and readings of the characters and their relationships. They have tweeted with "The Powers That Be," mobilized to filming locations via #Setlock, and become advocates for LGBTQIA communities.

Sherlock's digital communities have changed the way that fans and series creators interact in person and online, as each publicly takes "ownership" of beloved television characters who represent far more than entertainment to fans.