"[molly hooper], well, she's very key." - M.G. (Sherlock Uncover

Whose tragedy? As Sherlock said in TLD, your own death is something that happens to everybody else. The people around you. Your beloved ones. But Molly is alone, distant from her relatives, as Sherlock pointed out while staring at the coffin. And as far as we know, she has only talked about one person in her life: her father. And he’s dead, so we can confirm she’s a bit of a loner. Anyway, she’s a young, good-hearted and intelligent woman. And, of course, the death of a young person is always a sad event.

So, the meaning of Eurus’ quote (”It will be, as I understand it, a tragedy”) is entirely focused on Sherlock, because from all the people who keep in touch with Molly, he would be the most devastated. And we noticed it when he looked at the coffin, heavily breathing for realising it was meant for her…

Whose words would be left unsaid? Molly’s?  Sherlock’s?  BOTH.

Eurus wanted to make Molly say “I love you” to Sherlock. 

In fact, Eurus wanted to make Sherlock LISTEN to Molly’s confession. She wanted to make Sherlock UNDERSTAND that woman’s feelings and SEE her heart. The heart that’s always belonged to him. But Eurus also wanted to touch Sherlock’s heart. Make it bleed and hurt. And the only way to do all of this to him, was making him listen to those three words. Three sincere words he never heard in his entire life. The words said by someone with actual feelings for him. Actual love. Molly’s words.

So, what about HIS words? 

The words that first came out of his mouth in an awkward way, but then burst out again in a softer and genuine tone? His own words… Why did they agitate him so much? Why did they make him lose control? He said it was something “very easy” for Molly to say. But why wasn’t it easy for HIM?       

For sentiment has always been a chemical defect. And when it’s related to Sherlock Holmes, it means weakness and fear about the inevitable fact that, when you open your heart, you’re at a disadvantage.

Know this: this creature is the bringer of death. He will never eat, he will never sleep, and he will never stop.