Sherlock, a contemporary re-imagining of the Arthur Conan Doyle classic, co-created by Steven Moffat and Mark Gatiss, caused a sensation last season.
It was tweeted across the globe and mentioned in the House of Commons, delivering an audience of over nine-million viewers in the UK, who tuned into watch Sherlock and John Watson navigate a maze of cryptic clues and lethal killers in three thrilling, action-packed adventures.
Benedict Cumberbatch returns as Sherlock and is joined by Martin Freeman as Dr John Watson, Rupert Graves as Inspector Lestrade and Una Stubbs as Mrs Hudson.
Sherlock co-creators Steven Moffat and Mark Gatiss reveal that when it came to sharing the writing responsibilities, Steven chose to do the twisted love story (Scandal) whilst Mark chose the Gothic horror (Baskerville) and Stephen Thompson (Silk, Dr Who) wrote the thrilling finale (Reichenbach).
Sherlock 2 is directed by Paul McGuigan (Monroe) whose style and inventiveness contributed to the success of the first season and Toby Haynes (Doctor Who, Being Human).
Sue Vertue (Sherlock, Coupling) produced A Scandal In Belgravia and The Hounds Of Baskerville and is executive producer on The Reichenbach Fall, which is produced by Elaine Cameron (Jekyll).
The executive producers are Beryl Vertue, Mark Gatiss and Steven Moffat. The executive producer for BBC Cymru Wales is Bethan Jones. It is a Hartswood Films Production for BBC Cymru Wales, co-produced with Masterpiece. The executive producer for Masterpiece is Rebecca Eaton.
In the first episode of Season 2, entitled "A Scandal In Belgravia", compromising photographs and a case of blackmail threaten the very heart of the British establishment, but for Sherlock and John the game is on in more ways than one as they find themselves battling international terrorism, rogue CIA agents and a secret conspiracy involving the British government.
But this case will cast a darker shadow over their lives than they could ever imagine, as the great detective begins a long duel of wits with an antagonist as cold and ruthless and brilliant as himself: to Sherlock Holmes, Irene Adler will always be THE woman.
In Episode 2, "The Hounds of Baskerville", something terrible has happened to Henry Knight; Sherlock and John investigate the truth about the monstrous creature which apparently killed their client's father.
A hound from hell? What seems like fantasy in Baker Street is a very different prospect in the ultra-secret army base that looms over Dartmoor.
In the final episode of the season, "The Reichenbach Fall", James Moriarty possesses the greatest criminal mind that the world has ever seen. Sherlock and John knew he wouldn't stay hidden for long.
But even they never guessed the sheer scale and audacity of the crime that would propel Moriarty back into the headlines. The crime of the century. The Tower of London, the Bank of England and Pentonville prison - all sprung open on the same day, as if by magic!
But Moriarty's plans don't stop there...
Sherlock and John lock horns with their old enemy in one final problem that tests loyalty and courage to their very limits. Sherlock must fight for his reputation, his sanity and his life.
But is he all he claims to be?
Sherlock is written and created by Steven Moffat and Mark Gatiss, and inspired by the works of Sir Arthur Conan Doyle. Sherlock is produced by Sue Vertue and the executive producers are Beryl Vertue, Mark Gatiss and Steven Moffat for Hartswood Films, Bethan Jones for the BBC and Rebecca Eaton for Masterpiece.