Spoilers for Season 4, Episode 3 of Sherlock.
There is a theory floating around the internet that there is a secret 4th episode of Sherlock, which will air on Sunday, 22nd January.
I love interesting theories, so here are the main arguments (collected from around the web) that there will be a 4th episode:
There is a TV schedule which shows a 4th episode. (looks fake to me!)
Sherlock commented in Season 4, Episode 2 that people stop looking at 3. There was a fourth recording device, so why not a fourth episode?
The date on Sunday is 22/1 (UK date format) ‘221’ is the address of the Baker Street boys.
The TFP was emotional, less logical, because it takes place inside John’s head. John was actually shot by Eurus. If true, this would need to be resolved in a 4th episode.
The Piccadilly circus board in London has been turned off for renovations. There will be a temporary advertising banner. Some say that this will be Moriarty’s ‘Miss me,’ indicating that he will return on Sunday.
Amanda Abbington (who plays Mary) said:
(Sherlock Season 4 Extra bits) Some fans have taken ‘If we can pull this off, then it’s amazing,’ to mean that the writers are trying to pull off a secret 4th episode.
Sue Vertue, the producer, said in 2014 that: Sherlock might not always have 3 episodes per series
The security footage of Eurus shows EGY followed by the number 18992201 in the corner. Is EGY code for a new episode name, and 2201 Sunday’s date?
The 1899 could refer to a 4 act Sherlock Holmes play, that was first performed in 1899. The key thing being 4 acts, a hint to 4 episodes.
Moffat has denied rumours of a secret 4th episode though: Moffat on 4th Sherlock episode
But then, if it were true, he would, wouldn’t he?
Do I believe there will be a 4th episode?
It seems unlikely, but it would be cool if it were true, and we got a further episode with Moriarty. I will never say no to more of my favourite shows!
I loved The Final Problem. Perhaps it was intended as a final episode. Maybe they wanted to tie off this arc nicely? The lack of cliffhanger seems wrong though: we have not come to expect such a happy ending from the series.
Whether all this speculation turns out to be true or not, it is interesting to watch the theories unfold. I will watch BBC1 on Sunday night just in case, because you never know! (Actually, I’ll be watching Apple Tree Yard, because it looks good!)