Eurus Killed Redbeard
In the trailer for The Final Problem, Mycroft tells Sherlock âEvery choice youâve ever made, every path youâve ever taken, the man you are today is your memory of Eurus.âÂ
Mycroft sees his brother as someone, who, like him, disregards sentiment in favor of cold, calculated reason. Because of the innate human need to connect, abandoning sentiment completely is likely the result of a traumatic end to a sentimental relationship.Â
The fact that Mycroft always says âRedbeardâ to warn Sherlock about getting too emotionally close suggests that this was the initial trauma.Â
The flashbacks weâve been seeing are likely just before Redbeard was killed by his sister--itâs Sherlockâs last memory of being unafraid to love someone (a dog, but still).Â
Mycroftâs discussion of Eurus suggests she is extremely dangerous:Â
âIt didnât the last timeâ directly follows this, suggesting Euros is the same âlegitimate security concern.âÂ
âSherrinfordâ here likely suggests a mental asylum or prison, and a very high security one (this could very well be where all of the tortuous mind palace looking scenes weâve seen could be, but thatâs a whole different meta).Â
Murderous tendencies are obviously a security risk, and if Eurus has the psychopathy of a serial killer, that would necessitate the high security Mycroft suggests is necessary.Â
One of the first behaviors serial killers demonstrate is animal torture.
Mummy and Daddy Holmes would know this, and there would likely be signs that she was in danger of becoming a serial killer throughout her childhood. They likely tried many therapies, but nothing was working. And then Euros killed Redbeard, and they insitituonalized their daughter before she could move onto humans.Â
In those flashbacks, Sherlock is young, which explains why he wouldnât recognize her (even with his drug-addled state, he should have recognized her slightly if he had seen her at all recently). They Holmes family never talked about her. Itâs why Sherlock is basing his behavior on her âmemory,â not her presence.Â
The depth of Sherlockâs fear of attachment, stemming from Redbeard, suggests this wasnât an ordinary âdog grows old and diesâ story. There was trauma involved.Â
And nothing says trauma like watching your older (Iâm headcanoning that sheâs in between the brothers) sister kill your dog--two destroyed relationships at once.Â
Sherlock loved his sister and his dog, and because he let sentiment blind him (or Mycroft and the Holmes parents hid the signs from him), he lost both in one event. To protect himself, he built emotional barriers.Â
Itâs the path he chose--because of his traumatic memory of Eurus.Â
(Eurus spelling taken from BBC subtitles.)Â





















