Meaning

Three simple words, but their effect depends entirely on who is saying them and when. Moriarty had apparently died at the end of the previous series, and this sudden reappearance, accompanied by that breezy, taunting question, is designed to destabilize everyone watching, characters and audience alike. The line works as a taunt, an announcement, and a kind of dark flirtation all at once. It implies that the speaker knows he is theatrical, knows he has been missed, and is enormously pleased about both facts.

Context

The line appears in the brief post-credits sequence that closes the third series finale. It interrupted what had been a relatively contained and emotional episode, arriving as a shock designed to reopen the central conflict of the show. The moment was widely discussed after broadcast, in part because it was so minimal yet so effective. The character of Moriarty in this series is written as Holmes's intellectual mirror and theatrical opposite, and the line captures that quality perfectly: it is a villain's entrance that asks for applause.

About the author

Jim Moriarty in BBC Sherlock is reimagined from Conan Doyle's original Napoleon of Crime into a gleefully anarchic consulting criminal with a flair for performance and provocation. The character was written by Steven Moffat and Mark Gatiss and played by Andrew Scott, whose portrayal became widely celebrated for its unpredictability and dark humor. Scott's delivery gave lines like this one a quality that was simultaneously funny and genuinely unsettling.