The Sign of Three

"The Sign of Three" is the second episode of the third series of the BBC television series Sherlock. It was written by Stephen Thompson, Mark Gatiss and Steven Moffat, and stars Benedict Cumberbatch as Sherlock Holmes and Martin Freeman as Dr John Watson. The episode's title is inspired by The Sign of the Four by Sir Arthur Conan Doyle. It is set six months after the series opener "The Empty Hearse" and is primarily centred on the day of Watson's wedding to Mary Morstan. It garnered a viewership of 11.37 million, and received mostly positive reviews.