Filming and air date
The series was shot in two parts, with the first two episodes filmed in April and May, while work on the finale followed a summer break and wrapped on 1 September (for a fun look back at how it unfolded see our Sherlock series 3 filming diary).
When will we get to watch it? While a lucky few members of the British Film Institute will get to see a preview screening of the first epsiode on 15 December, early 2014 is the closest that official sources will come to naming an actual air date. It's worth noting, though, that series two kicked off on New Year's Day 2012. Now wouldn't that be a great start to the year?
In August 2012 Steven Moffat and Mark Gatiss revealed three key words, one relating to each episode of the new series. They've since told us the full titles (all pleasing puns on original Sherlock Holmes stories) and also dropped other clues, and even a few facts. Here's what we know so far, plus a great deal of educated speculation...
Episode 1 – The Empty Hearse/"Rat”
Writer: Mark Gatiss (The Great Game, The Hounds of Baskerville)
Director: Jeremy Lovering
Guest cast: Amanda Abbington, Sharon Rooney as Laura
This is the episode we know the most about. Written by Mark Gatiss, it will answer the question every Sherlock fan is asking – “How did he survive the fall?” Martin Freeman tells us "All the clues were on screen. It's not going to be a cheat – everything that we saw on that final episode offers hints as to how he did it."
But how will Sherlock reveal himself to his friend, and how will John react? We already know from Gatiss (and the title) that the episode will be based in part on The Adventure of the Empty House, the story in which Sir Arthur Conan Doyle resurrected Holmes. In the original, the detective bumps into Dr Watson while disguised as a stooped, elderly book seller and only reveals himself once he’s finagled his way safely inside 221B Baker Street. But Gatiss says we will not be looking at a traditional disguise-and-reveal: "He actually has a line in [series one finale] the Great Game which is ‘The art of disguise is knowing how to hide in plain sight’ and that was because, right from the start, I thought modern day Sherlock Holmes would not put putty noses on, he would basically be standing behind you now and you wouldn’t know he was there."
One way or another, though, Sherlock will have to reveal himself. So what might be John’s reaction when he does? The literary Dr Watson faints at the sight of his friend's face, and is then simply overjoyed to see him, but Gatiss has strongly suggested that John is likely to be less understanding. "I always found it a little unlikely that Dr Watson's only reaction was to faint... as opposed to possibly a stream of terrible swear words," said Gatiss (and knowing John and Sherlock's history, a smack in the mouth is not out of the question either).
With unpleasantries out of the way and the duo back together, what’s next? In The Empty House, Holmes is on the run from Moriarty’s vengeful henchmen, in particular his second in command, bushy-moustached sharp-shooter Colonel Sebastian Moran, who is stationed in the house opposite with an air rifle waiting to blow Holmes’s brains out. When Sherlock fell to his “death” at the end of series two, the hitmen targetting John, Mrs Hudson and Lestrade packed up their guns but if they find out the detective is still alive they could be back. It would therefore seem imperative that Sherlock’s return is kept secret from the world until that issue is dealt with.
More recently, Mark Gatiss revealed that the episode is "explicitly about the London Underground" – and following the release of the first synopsis, we know that Sherlock will be attempting to foil a terrorist attack on the capital. As real Londoners are only too aware, the Tube network is likely to be a prime target...
The next thing to consider is the possible significance of the word “Rat”. In Doyle story The Boscombe Valley Mystery, “Rat” turns out to be a fragment of a word which reveals the origin of a murderer. It’s also been suggested it could be a reference to “the giant rat of Sumatra,” a case which Holmes only alludes to in the original stories, calling it “a story for which the world is not yet prepared.” It’s possible that BBC viewers are not yet prepared for a giant rodent stalking the streets of London either and it's at this point we should remind ourselves of what Steven Moffat said after revealing the three words: "[they] may be misleading, are not titles, are only teases or possibly clues, but might be deliberately designed to get you into a lather."
Martin Freeman's partner Amanda Abbington is expected to make her first appearance in this episode (for more on who she might be playing, see below) while Sharon Rooney, star of My Mad Fat Diary, will also guest, as a character named Laura.
Episode 2 – The Sign of Three/“Wedding”
Writer: Stephen Thompson (The Blind Banker, The Reichenbach Fall)
Director: Colm McCarthy
Guest cast: Amanda Abbington, Nicholas Asbury as The Landlord, Helen Bradbury as Emma, Laura Dale as The Girl, Alfred Enoch as Bainbridge
Wedding was the key word mentioned by Mark Gatiss and Steven Moffat, before we knew anything else about the episodes, and during filming in April producer Sue Vertue (Moffat's wife) tweeted the photo left that confirmed Sherlock would indeed be attending a wedding in the new series. But what wedding?! Whose wedding?!
As much as some fans might like to see Sherlock forming a brainy-sexy power couple with “The Woman” Irene Adler (or making lab geek Molly Hooper’s dreams come true) it seems highly unlikely that the self-confessed “high-functioning sociopath” is in the market for long-term commitment with a member of the fairer sex (unless you count his lease with landlady Mrs Hudson).
John, on the other hand, is a different matter. He’s been testing out various prospective partners throughout the series, and in the original stories Dr Watson does indeed settle down, with one Mary Morstan, heroine of novel... The Sign of Four.
We even have a very good idea who John will be marrying. The announcement that Martin Freeman’s real-life partner Amanda Abbington is to appear in the new series is, on its own, hardly grounds to believe that life is going to imitate art. But look a little closer and there are certainly some points of interest...
In the Arthur Conan Doyle tales, Dr Watson's marriage meets his future wife when she asks Holmes to investigate her father's disappearance. Their subsequent marriage sees Watson moving out of his Baker Street rooms and having increasingly less contact with his friend.
So when we hear that filming on series three of Sherlock has involved Abbington's character running around with the detective – presumably on a case – and then the BBC tells us she will be taking on “a role that significantly impacts upon the lives of John and Sherlock”, well, it all fits together rather neatly...
Episode 3 – His Last Vow/"Bow"
Writer: Steven Moffat (A Study in Pink, A Scandal in Belgravia)
Director: Nick Hurran
Guest cast: Lars Mikkelsen as Charles Augustus Magnussen, Amanda Abbington, Tim Wallers as John Garvie
As any Sherlock Holmes aficionado will know, His Last Bow is the name of Sherlock Holmes's final adventure (chronologically speaking, that is – 12 more were published afterwards, but all were set prior to it).
It sees the detective turn spy (he even gets a codename: Altamont) to help Britain in the war effort against Germany. Thankfully, we're not at war in 21st century Britain, but given Sherlock's connections to Whitehall it's not a massive leap to think that he might be called upon by Queen, country and brother Mycroft.
However... we already know there is to be a fourth series of Sherlock (phew!) and that this episode will feature a villain based on a character from a different original story.
In name at least, Charles Augustus Magnussen, is based on Charles Augustus Milverton the "king of all blackmailers", a ruthless character who Holmes describes as more distasteful than any of the many murderers he has encountered during his career. Milverton makes his living by extorting money from his victims using ill-gotten scandalous revelations about their personal lives.
Danish actor Lars Mikkelsen, best known to UK audiences as mayoral candidate Troels Hartmann in Nordic Noir hit The Killing will play Magnussen, and our first glimpse of him suggests a very different, less flambouyant villain to Moriarty.
Meanwhile, you may be interested to know that the original story not only involves Sherlock taking on the guise of a plumber in order to gain information about Milverton but also sees him betrothed to the villain's housemaid...