I've been speculating on where The Final Problem might take us... I think this topic is the closest fit for my latest theory. Bear with me, I ramble a bit, but it is about Eurus.

Spoilers for a The Valley of Fear (VALL)...

So, one of the code names Mycroft mentions at the start of The Six Thatchers was "Porlock", who was a minor character in The Valley of Fear. Porlock was an informer connected with Moriarty. He sent Holmes an encrypted warning about a threat to a man called John Douglas, who lives in a big country manor called Birlstone House. Long story short, Douglas turns out to be ex-Pinkerton detective Birdy Edwards. You can read more about the plot here  https://en.m.wikipedia.org/wiki/The_Valley_of_Fear

Moftiss are good at playing mix and match with canon, so I'm sure it won't play out exactly like the ACD story, but there are a few possible indicators that they have adapted it. What if Porlock is Sir Edwin, and Eurus is Birdy Edwards, an undercover MI6 agent? Eurus is the East Wind, the terrifying force that lays waste to all in its path, seeking out the unworthy and plucking them from the earth – a good description of Birdy Edwards if you think about it.

This would explain why Eurus is a secret, never mentioned by any of the Holmes family; why Lady Smallwood and Sir Edwin know about "the other one"; why she is a risk to national security; why she would need to be "secure." It could also explain why she's so good at changing her appearance and accent etc. Sherrinford could be another of her aliases. One problem with this theory is the fact that Sherlock hasn't recognised her as his sister... maybe she's had facial reconstruction surgery! Maybe she's been presumed dead for a long time. Maybe Sherlock has deleted her from his memory.

In VALL, "Douglas" gets shot in the face, but it turns out not to be him; we apparently see John getting shot in the face at the end of The Lying Detective. Or how about this... Birdy Edwards had to pretend to be a hard case to infiltrate a criminal gang called The Scowrers (could be Moriarty's network in this case) and did all sorts of nasty stuff to convince the gang leader that he was one of them, in order to bring them to justice. If Eurus is still working undercover to bring down his network, maybe "shooting" John will all be a ruse. Maybe she hasn't really killed John's new therapist, but only made it look like she has. The psychopath persona could all be an act. I personally hope this is the case, as I would like to think that all of the Holmeses are really on the side of the angels.

Moriarty or his (twin) brother or whoever the heck is in the trailer, wants to burn the heart out of Sherlock and solve the Final Problem. Perhaps he has sent Eurus to destroy Sherlock but doesn't realise she is Sherlock's own sister.

You never know how Moftiss might twist things around. But other fragments fit. There's the "Miss Me" note that Sherlock had to decipher. The big manor house we see burning in the trailer could have something to do with it. Three people (Holmes, Watson and NSY Inspector MacDonald) go to Birlstone, Sussex to investigate; in the trailer for The Final Problem we see Sherlock, John and Mycroft working together in a strange location. Okay, maybe I'm grasping at straws now!

What does everyone else think?

Last edited by Meretricious (January 15, 2017 6:43 am)