I loved Eurus Holmes quite a lot, and Sian Brooke was absolutely amazing. BUT. Imagine a Newtonian-level Eurus Holmes with a scope and goals beyond getting her brothers’ attention. Imagine an anti-hero, big picture, sacrifices-must-be-made-for-the-greater-good Eurus, who wants to save the world and isn’t worried about who might get hurt along the way.
Imagine five year old Eurus realizing that Victor Trevor is only ever going to amount to a mid-level banker who occasionally hits his wife, but his death would push her brother to be the greatest detective the world has ever known. Hundreds, maybe thousands of lives can be saved. No brainer. Into the well he goes.
Imagine 20 year old Eurus realizing that she can save the world, and all she has to do is burn it down first. She knows just how to pull the threads that will create a lasting utopia on planet earth within 100 years. Yes, 4 billion or so people will die along the way, but the earth is overcrowded anyway. She sets about her work, manipulating poor Uncle Rudy and her older brother and the idiots at Sherrinford along the way. At first her access is limited, but she learned patience at an early age.
It gets lonely. She decides to seek out a little helpmeet in her adventures. She knows there is no one else in the world who can match her intellect, but she needs someone who is both smart enough to keep up with her and flexible enough to do what needs to be done. Someone who is not boring. She hopes she’s found that in Jim Moriarty, but within 20 seconds of meeting him she knows that he’s too invested in burning the world down to ever want to rebuild it again afterwards. Ample observation has confirmed that Mycroft, while more intelligent, does not possess the necessary mental and moral flexibility. A quick twitter search confirms that there are no other serious contenders - it will have to be Sherlock.
She sets her nets and she waits. Dear Jim is invaluable in this endeavor. She devises a series of trials that will teach Sherlock about the weakness of sentiment, drive him away from his pets (er…“friends”), and to make difficult decisions for the greater good. She carefully calculates the variables and concludes that once he has killed their brother, he will be ready to listen to what she has to say. She can be very persuasive.
But the day arrives and Sherlock not only refuses to kill their brother, he is prepared to die for him. Eurus is wrong. WRONG. She has never been wrong in her life. If she’s wrong about this, her own brother, what else could she have miscalculated? Could she have been prepared to sacrifice 4 billion lives on incorrect data? Eurus retreats into her own mind, shattered by her failure, destined to spend the rest of her life seeking the one variable she will never understand - love. Sentiment. Amo.